Please put answers below the boxes 1) A politician claims that he is supported by a clear majority of voters. In a recent survey, 35 out of 51 randomly selected voters indicated that they would vote for the politician. Use a 5% significance level for the test. Use Table 1. a. Select the null and the alternative hypotheses. H0: p = 0.50; HA: p ≠ 0.50 H0: p ≤ 0.50; HA: p > 0.50 H0: p ≥ 0.50; HA: p < 0.50 b. Calculate the sample proportion. (Round your answer to 3 decimal places.) Sample proportion c. Calculate the value of test statistic. (Round intermediate calculations to 4 decimal places. Round your answer to 2 decimal places.) Test statistic d. Calculate the p-value of the test statistic. (Round intermediate calculations to 4 decimal places. Round "z" value to 2 decimal places and final answer to 4 decimal places.) p-value e. What is the conclusion? Do not reject H0; the politician is not supported by a clear majority Do not reject H0; the politician is supported by a clear majority Reject H0; the politician is not supported by a clear majority Reject H0; the politician is supported by a clear majority 2) Consider the following contingency table. B Bc A 22 24 Ac 28 26 a. Convert the contingency table into a joint probability table. (Round your intermediate calculations and final answers to 4 decimal places.) B Bc Total A Ac Total b. What is the probability that A occurs? (Round your intermediate calculations and final answer to 4 decimal places.) Probability c. What is the probability that A and B occur? (Round your intermediate calculations and final answer to 4 decimal places.) Probability d. Given that B has occurred, what is the probability that A occurs? (Round your intermediate calculations and final answer to 4 decimal places.) Probability e. Given that Ac has occurred, what is the probability that B occurs? (Round your intermediate calculations and final answer to 4 decimal places.) Probability f. Are A and B mutually exclusive events? Yes because P(A | B) ≠ P(A). Yes because P(A ∩ B) ≠ 0. No because P(A | B) ≠ P(A). No because P(A ∩ B) ≠ 0. g. Are A and B independent events? Yes because P(A | B) ≠ P(A). Yes because P(A ∩ B) ≠ 0. No because P(A | B) ≠ P(A). No because P(A ∩ B) ≠ 0. 3) A hair salon in Cambridge, Massachusetts, reports that on seven randomly selected weekdays, the number of customers who visited the salon were 72, 55, 49, 35, 39, 23, and 77. It can be assumed that weekday customer visits follow a normal distribution. Use Table 2. a. Construct a 90% confidence interval for the average number of customers who visit the salon on weekdays. (Round intermediate calculations to 4 decimal places, "sample mean" and "sample standard deviation" to 2 decimal places and "t" value to 3 decimal places, and final answers to 2 decimal places.) Confidence interval to b. Construct a 99% confidence interval for the average number of customers who visit the .

1. Please put answers below the boxes
1)
A politician claims that he is supported by a clear majority of
voters. In a recent survey, 35 out of 51 randomly selected voters
indicated that they would vote for the politician. Use a 5%
significance level for the test. Use Table 1.
a.
Select the null and the alternative hypotheses.
H0: p = 0.50; HA: p ≠ 0.50
H0: p ≤ 0.50; HA: p > 0.50
H0: p ≥ 0.50; HA: p < 0.50
b.
Calculate the sample proportion. (Round your answer to 3
decimal places.)
Sample proportion
c.
Calculate the value of test statistic. (Round intermediate
calculations to 4 decimal places. Round your answer to 2
decimal places.)
Test statistic

2. d.
Calculate the p-value of the test statistic. (Round intermediate
calculations to 4 decimal places. Round "z" value to 2 decimal
places and final answer to 4 decimal places.)
p-value
e.
What is the conclusion?
Do not reject H0; the politician is not supported by a clear
majority
Do not reject H0; the politician is supported by a clear majority
Reject H0; the politician is not supported by a clear majority
Reject H0; the politician is supported by a clear majority
2)
Consider the following contingency table.
B
Bc
A
22
24
Ac

3. 28
26
a.
Convert the contingency table into a joint probability table.
(Round your intermediate calculations and final answers to 4
decimal places.)
B
Bc
Total
A
Ac
Total
b.
What is the probability that A occurs? (Round your intermediate
calculations and final answer to 4 decimal places.)
Probability
c.
What is the probability that A and B occur? (Round your

4. intermediate calculations and final answer to 4 decimal places.)
Probability
d.
Given that B has occurred, what is the probability that A
occurs? (Round your intermediate calculations and final answer
to 4 decimal places.)
Probability
e.
Given that Ac has occurred, what is the probability that B
occurs? (Round your intermediate calculations and final answer
to 4 decimal places.)
Probability
f.
Are A and B mutually exclusive events?
Yes because P(A | B) ≠ P(A).
Yes because P(A ∩ B) ≠ 0.
No because P(A | B) ≠ P(A).
No because P(A ∩ B) ≠ 0.

5. g.
Are A and B independent events?
Yes because P(A | B) ≠ P(A).
Yes because P(A ∩ B) ≠ 0.
No because P(A | B) ≠ P(A).
No because P(A ∩ B) ≠ 0.
3)
A hair salon in Cambridge, Massachusetts, reports that on seven
randomly selected weekdays, the number of customers who
visited the salon were 72, 55, 49, 35, 39, 23, and 77. It can be
assumed that weekday customer visits follow a normal
distribution. Use Table 2.
a.
Construct a 90% confidence interval for the average number of
customers who visit the salon on weekdays. (Round
intermediate calculations to 4 decimal places, "sample mean"
and "sample standard deviation" to 2 decimal places and "t"
value to 3 decimal places, and final answers to 2 decimal
places.)
Confidence interval
to
b.
Construct a 99% confidence interval for the average number of
customers who visit the salon on weekdays. (Round

6. intermediate calculations to 4 decimal places, "sample mean"
and "sample standard deviation" to 2 decimal places and "t"
value to 3 decimal places, and final answers to 2 decimal
places.)
Confidence interval
to
c.
What happens to the width of the interval as the confidence
level increases?
As the confidence level increases, the interval becomes
narrower and less precise.
As the confidence level increases, the interval becomes wider
and less precise.
4)
Consider the following sample data:
x
22

7. 36
10
31
11
37
28
32
y
28
44
36
36
34
37
39
33
Click here for the Excel Data File
b.
Calculate b1 and b0. What is the sample regression equation?
(Round intermediate calculations to 4 decimal places and final
answers to 2 decimal places.)
y-hat = + x
c.
Find the predicted value for y if x equals 12, 17, and 22. (Round
intermediate coefficient values and final answers to 2 decimal
places.)
y-hat
If x = 12
If x = 17

8. If x = 22
5)
India is the second most populous country in the world, with a
population of over 1 billion people. Although the government
has offered various incentives for population control, some
argue that the birth rate, especially in rural India, is still too
high to be sustainable. A demographer assumes the following
probability distribution of the household size in India.
Household Size
Probability
1
0.04
2
0.13
3
0.15
4
0.22
5
0.17
6
0.15
7
0.11
8
0.03
a.
What is the probability that there are less than 5 members in a
typical household in India? (Round your answer to 2 decimal
places.)

9. Probability
b.
What is the probability that there are 5 or more members in a
typical household in India? (Round your answer to 2 decimal
places.)
Probability
c.
What is the probability that the number of members in a typical
household in India is greater than 4 and less than 7 members?
(Round your answer to 2 decimal places.)
Probability
6)
Consider the following population data:
22
28
10
12
8
a.
Calculate the range.

10. Range
b.
Calculate MAD. (Round your intermediate calculations to 4
decimal places and final answer to 2 decimal places.)
MAD
c.
Calculate the population variance. (Round your intermediate
calculations to 4 decimal places and final answer to 2 decimal
places.)
Population variance
d.
Calculate the population standard deviation. (Round your
intermediate calculations to 4 decimal places and final answer
to 2 decimal places.)
Population standard deviation
7)
On a particularly busy section of the Garden State Parkway in
New Jersey, police use radar guns to detect speeders. Assume
the time that elapses between successive speeders is
exponentially distributed with a mean of 19 minutes.
a.
Calculate the rate parameter λ. (Round your answer to 4 decimal
places.)

11. Rate parameter λ
b.
What is the probability of a waiting time less than 13 minutes
between successive speeders? (Round your answer to 4 decimal
places.)
Probability
c.
What is the probability of a waiting time in excess of 27
minutes between successive speeders? (Round your answer to 4
decimal places.)
Probability
8)
The following ANOVA table was obtained when estimating a
multiple regression.
ANOVA
df
SS
MS
F
Significance F
Regression
2
188,492.30
94,246.15
60.08
4.86E-11
Residual

12. 29
45,490.50
1,568.64
Total
31
233,982.80
a.
Calculate the standard error of the estimate. (Round your
answer to 2 decimal places.)
se
b-1.
Calculate the coefficient of determination. (Round your answer

13. to 4 decimal places.)
Coefficient of determination
b-2.
Interpret the coefficient of determination.
The proportion of the variation in x that is explained by the
regression model.
The proportion of the variation in y that is explained by the
regression model.
c.
Calculate adjusted R2. (Round your answer to 4 decimal
places.)
Adjusted R2
9)
In order to estimate the mean 30-year fixed mortgage rate for a
home loan in the United States, a random sample of 17 recent
loans is taken. The average calculated from this sample is
4.85%. It can be assumed that 30-year fixed mortgage rates are
normally distributed with a standard deviation of 0.5%.
Compute 90% and 95% confidence intervals for the population
mean 30-year fixed mortgage rate. Use Table 1. (Round
intermediate calculations to 4 decimal places, "z" value and
final answers to 2 decimal places. Enter your answers as
percentages, not decimals.)
Confidence Level

14. Confidence Interval
90%
%
to
%
95%
%
to
10)
Consider the following hypotheses:
H0: p ≥ 0.37
HA: p < 0.37
Which of the following sample information enables us to reject
the null hypothesis at α = 0.05 and at
α = 0.10? Use Table 1.
α = 0.05
α = 0.10
a.
x = 33; n = 100
b.
x = 80; n = 285
c.
= 0.34; n = 58

15. d.
= 0.34; n = 416
a. Reject or Do not reject
11)
In a multiple regression with two explanatory variables and 117
observations, it is found that SSR = 4.51 and SST = 8.86.
a.
Calculate the standard error of the estimate. (Round your
answer to 2 decimal places.)
se
b.
Calculate the coefficient of determination R2. (Round your
answer to 4 decimal places.)
R2
c.
Calculate adjusted R2. (Round your answer to 4 decimal
places.)
Adjusted R2
12)
A retailer is looking to evaluate its customer service.
Management has determined that if the retailer wants to stay
competitive, then it will have to have at least a 91% satisfaction
rate among its customers. Management will take corrective

16. actions if the satisfaction rate falls below 91%. A survey of
1,450 customers showed that 1,305 were satisfied with their
customer service. Use Table 1.
a.
Select the hypotheses to test if the retailer needs to improve its
services.
H0: p = 0.91; HA: p ≠ 0.91
H0: p ≥ 0.91; HA: p < 0.91
H0: p ≤ 0.91; HA: p > 0.91
b.
What is the value of the appropriate test statistic? (Negative
value should be indicated by a minus sign. Round intermediate
calculations to 4 decimal places. Round your answer to 2
decimal places.)
Test statistic
c.
Compute the p-value. (Round "z" value to 2 decimal places and
final answer to 4 decimal places.)
p-value
d.
What is the conclusion?

17. The management will take corrective action.
The management will not take corrective action.
13)
Consider the following hypotheses:
H0: μ = 360
HA: μ ≠ 360
The population is normally distributed with a population
standard deviation of 73. Use Table 1.
a.
Use a 10% level of significance to determine the critical
value(s) of the test. (Round your answer to 2 decimal places.)
Critical value(s)
±
b-1.
Calculate the value of the test statistic with = 389 and n = 80.
(Round intermediate calculations to 4 decimal places. Round
your answer to 2 decimal places.)
Test statistic
b-2.
What is the conclusion at α = 0.10?

18. Do not reject H0 since the value of the test statistic is smaller
than the critical value.
Do not reject H0 since the value of the test statistic is greater
than the critical value.
Reject H0 since the value of the test statistic is smaller than the
critical value.
Reject H0 since the value of the test statistic is greater than the
critical value.
c.
Use a 5% level of significance to determine the critical value(s)
of the test. (Round your answer to 2 decimal places.)
Critical value(s)
±
d-1.
Calculate the value of the test statistic with = 335 and n = 80.
(Negative value should be indicated by a minus sign. Round
intermediate calculations to 4 decimal places. Round your
answer to 2 decimal places.)
Test statistic
d-2.
What is the conclusion at α = 0.05?

19. Reject H0 since the value of the test statistic is not less than the
negative critical value.
Reject H0 since the value of the test statistic is less than the
negative critical value.
Do not reject H0 since the value of the test statistic is not less
than the negative critical value.
Do not reject H0 since the value of the test statistic is less than
the negative critical value.
14)
Use computer) Assume that X is a hypergeometric random
variable with N = 55, S = 18, and n = 14. Calculate the
following probabilities. (Round your answers to 4 decimal
places.)
a.P(X = 8)
b.P(X ≥ 2)
c.P(X ≤ 4)
15)
For a sample of 41 New England cities, a sociologist studies the
crime rate in each city (crimes per 100,000 residents) as a
function of its poverty rate (in %) and its median income (in
$1,000s). The regression results are shown.

20. ANOVA
df
SS
MS
F
Significance F
Regression
2
3,519,512
1,759,756.0
10.29454
5.9E-04
Residual
24
4,102,577
170,940.7
Total
26
7,622,089

21. a.
Calculate the standard error of the estimate. (Round your
answer to 2 decimal places.)
b-1.
What proportion of the variability in crime rate is explained by
the variability in the explanatory variables? (Round your answer
to 4 decimal places.)
Explained proportion
b-2.
What proportion is unexplained? (Round your answer to 4
decimal places.)
Unexplained proportion
16)
Consider the following simple linear regression results based on
20 observations. Use Table 2.
Coefficients
Standard Error
t Stat
p-value
Lower 95%

22. Upper 95%
Intercept
33.8605
4.4081
7.6814
0.0000
24.60
43.12
x1
0.3634
0.1204
3.0183
0.0074
0.11
0.62
a-1.
Choose the hypotheses to determine if the intercept differs from
zero.
H0: β0 ≥ 0; HA: β0 < 0
H0: β0 ≤ 0; HA: β0 > 0
H0: β0 = 0; HA: β0 ≠ 0
a-2.
At the 5% significance level, what is the conclusion to the
hypothesis test? Does the intercept differ from zero?

23. Do not reject H0 the intercept is greater than zero.
Reject H0 the intercept is greater than zero.
Reject H0 the intercept differs from zero.
Do not reject H0 the intercept differs from zero.
b-1.
Construct the 95% confidence interval for the slope coefficient.
(Negative values should be indicated by a minus sign.Round
your intermediate calculations to 4 decimal places,"tα/2,df"
value to 3 decimal places and final answers to 2 decimal
places.)
Confidence interval
to
b-2.
At the 5% significance level, does the slope differ from zero?
Yes, since the interval does not contain zero.
No, since the interval contains zero.
Yes, since the interval contains zero.
No, since the interval does not contain zero.

24. 17)
Consider the following hypotheses:
H0: μ = 33
HA: μ ≠ 33
The population is normally distributed. A sample produces the
following observations:
38
31
34
36
33
38
28
Use the p-value approach to conduct the test at a 5% level of
significance. Use Table 2.
Click here for the Excel Data File
a.
Find the mean and the standard deviation. (Round intermediate
calculations to 4 decimal places. Round your answers to 2
decimal places.)

25. Mean
Standard deviation
b.
Calculate the value of the test statistic. (Round intermediate
calculations to 4 decimal places. Round your answer to 2
decimal places.)
Test statistic
c.
Approximate the p-value of the test statistic.
0.05 < p-value < 0.10
p-value > 0.20
0.10 < p-value < 0.20
d.
What is the conclusion?
Reject H0 since the p-value is greater than α.

26. Reject H0 since the p-value is smaller than α.
Do not reject H0 since the p-value is greater than α.
Do not reject H0 since the p-value is smaller than α.
18)
Let P(A) = 0.59, P(B) = 0.24, and P(A ∩ B) = 0.14.
a.
Calculate P(A | B). (Round your answer to 2 decimal places.)
P(A | B)
b.
Calculate P(A U B). (Round your answer to 2 decimal places.)
P(A U B)
c.
Calculate P((A U B)c). (Round your answer to 2 decimal
places.)
P((A U B)c)
19)
The time required to assemble an electronic component is
normally distributed with a mean and a standard deviation of 34
minutes and 20 minutes, respectively. Use Table 1.
a.
Find the probability that a randomly picked assembly takes

27. between 26 and 40 minutes. (Round "z" value to 2 decimal
places and final answer to 4 decimal places.)
Probability
b.
It is unusual for the assembly time to be above 56 minutes or
below 13 minutes. What proportion of assembly times fall in
these unusual categories? (Round "z" value to 2 decimal places
and final answer to 4 decimal places.)
Proportion of assembly times
20)
Christine has always been weak in mathematics. Based on her
performance prior to the final exam in Calculus, there is a 55%
chance that she will fail the course if she does not have a tutor.
With a tutor, her probability of failing decreases to 25%. There
is only a 65% chance that she will find a tutor at such short
notice.
a.
What is the probability that Christine fails the course? (Round
your answer to 4 decimal places.)
Probability
b.
Christine ends up failing the course. What is the probability that
she had found a tutor? (Round your answer to 4 decimal places.)
Probability

28. 21)
Consider the following returns for two investments, A and B,
over the past four years:
Investment 1:
5%
13%
–2%
7%
Investment 2:
3%
10%
–8%
13%
a-1.
Calculate the mean for each investment. (Round your answers to
2 decimal places.)
Mean
Investment 1
percent
Investment 2
percent
a-2.
Which investment provides the higher return?

29. Investment 2
Investment 1
b-1.
Calculate the standard deviation for each investment. (Round
your answers to 2 decimal places.)
Standard
Deviation
Investment 1
Investment 2
b-2.
Which investment provides less risk?
Investment 1
Investment 2
c-1.
Given a risk-free rate of 1.2%, calculate the Sharpe ratio for
each investment. (Do not round intermediate calculations.
Round your answers to 2 decimal places.)

30. Sharpe Ratio
Investment 1
Investment 2
c-2.
Which investment has performed better?
Investment 2
Investment 1
22)
Market observers are quite uncertain whether the stock market
has bottomed out from the economic meltdown that began in
2008. In an interview on March 8, 2009, CNBC interviewed two
prominent economists who offered differing views on whether
the U.S. economy was getting stronger or weaker. An investor
not wanting to miss out on possible investment opportunities
considers investing $20,000 in the stock market. He believes
that the probability is 0.30 that the market will improve, 0.37
that it will stay the same, and 0.33 that it will deteriorate.
Further, if the economy improves, he expects his investment to
grow to $28,000, but it can also go down to $17,000 if the
economy deteriorates. If the economy stays the same, his
investment will stay at $20,000.
a.

31. What is the expected value of his investment?
Expected value
$
b.
What should the investor do if he is risk neutral?
Investor invest the $20,000.
c.
Is the decision clear-cut if he is risk averse?
Yes
No
23)
A car manufacturer is concerned about poor customer
satisfaction at one of its dealerships. The management decides
to evaluate the satisfaction surveys of its next 66 customers.
The dealer will be fined if the number of customers who report
favorably is between 26 and 33. The dealership will be
dissolved if fewer than 26 report favorably. It is known that
62% of the dealer’s customers report favorably on satisfaction
surveys. Use Table 1.
a.
What is the probability that the dealer will be fined? (Round
intermediate calculations to 4 decimal places, “z” value to 2

32. decimal places, and final answer to 4 decimal places.)
Probability
b.
What is the probability that the dealership will be dissolved?
(Round intermediate calculations to 4 decimal places, “z” value
to 2 decimal places, and final answer to 4 decimal places.)
Probability
24)
The historical returns on a balanced portfolio have had an
average return of 10% and a standard deviation of 14%. Assume
that returns on this portfolio follow a normal distribution. Use
the empirical rule for normal distributions to answer the
following questions.
a.
What percentage of returns were greater than 38%? (Round your
answer to 1 decimal place.)
Percentage of returns
%
b.
What percentage of returns were below −18%? (Round your
answer to 1 decimal place.)
Percentage of returns
%
25)
A machine that is programmed to package 5.35 pounds of cereal

33. is being tested for its accuracy. In a sample of 16 cereal boxes,
the sample mean filling weight is calculated as 5.35 pounds. It
can be assumed that filling weights are normally distributed
with a population standard deviation of 0.04 pound. Use Table
1.
a-1.
Identify the relevant parameter of interest for these quantitative
data.
The parameter of interest is the proportion filling weight of all
cereal packages.
The parameter of interest is the average filling weight of all
cereal packages.
a-2.
Compute the point estimate as well as the margin of error with
95% confidence. (Round intermediate calculations to 4 decimal
places. Round "z" value and final answers to 2 decimal places.)
Point estimate
Margin of error
b-1.
Calculate the 95% confidence interval. (Use rounded margin of
error. Round your answers to 2 decimal places.)

34. Confidence interval
to
b-2.
Can we conclude that the packaging machine is operating
improperly?
Yes, since the confidence interval contains the target filling
weight of 5.35.
Yes, since the confidence interval does not contain the target
filling weight of 5.35.
No, since the confidence interval contains the target filling
weight of 5.35.
No, since the confidence interval does not contain the target
filling weight of 5.35.
c.
How large a sample must we take if we want the margin of error
to be at most 0.01 pound with 95% confidence? (Round
intermediate calculations to 4 decimal places.Round "z" value
to 2 decimal places and round up your final answer to the next
whole number.)
Sample size
26)
Consider the following hypotheses:

35. H0: μ ≥ 100
HA: μ < 100
The population is normally distributed. A sample produces the
following observations:
88
77
100
83
102
96
Use the critical value approach to conduct the test at a 5% level
of significance. Use Table 2.
a.
Find the mean and the standard deviation. (Round intermediate
calculations to 4 decimal places. Round your answers to 2
decimal places.)
Mean
Standard deviation

36. b.
Calculate the value of the test statistic. (Negative value should
be indicated by a minus sign. Round intermediate calculations
to 4 decimal places. Round your answer to 2 decimal places.)
Test statistic
c.
Calculate the critical value of the test statistic. (Negative value
should be indicated by a minus sign. Round intermediate
calculations to 4 decimal places. Round your answer to 3
decimal places.)
Critical value
d.
What is the conclusion?
Do not reject H0 since the value of the test statistic is less than
the negative critical value.
Do not reject H0 since the value of the test statistic is not less
than the negative critical value.
Reject H0 since the value of the test statistic is less than the
negative critical value.
Reject H0 since the value of the test statistic is not less than the
negative critical value.

37. 27)
In a simple linear regression, the following information is
given:
= − 23; = 42;
a.
Calculate b1. (Negative value should be indicated by a minus
sign. Round your answer to 2 decimal places.)
b1
b.
Calculate b0. (Round intermediate calculations to 4 decimal
places and final answer to 2 decimal places.)
b0
c-1.
What is the sample regression equation? (Negative value should
be indicated by a minus sign. Round your answers to 2 decimal
places.)
y-hat = + x
c-2.
Predict y if x equals −22.(Round intermediate coefficient values
and final answer to 2 decimal places.)

38. y-hat
28)
Using data from 50 workers, a researcher estimates Wage = β0
+ β1 Education + β2 Experience +β3 Age + ε, where Wage is
the hourly wage rate and Education, Experience, and Age are
the years of higher education, the years of experience, and the
age of the worker, respectively. A portion of the regression
results is shown in the following table.
Coefficients
Standard Error
t Stat
p-value
Intercept
7.27
3.99
1.43
0.0629
Education
1.03
0.37
3.54
0.0001
Experience
0.43
0.11
3.23
0.0020
Age
−0.01
0.06
−0.10
0.7920

39. a-1.
What is the point estimate for β1?
1.03
0.43
a-2.
Interpret this value.
As Education increases by 1 unit, Wage is predicted to increase
by 1.03 units.
As Education increases by 1 unit, Wage is predicted to increase
by 0.43 units, holding Age and Experience constant.
As Education increases by 1 unit, Wage is predicted to increase
by 1.03 units, holding Age and Experience constant.
As Education increases by 1 unit, Wage is predicted to increase
by 0.43 units.
a-3.
What is the point estimate for β2?
0.43
1.03

40. a-4.
Interpret this value.
Same interpretation by using 1.03 or -0.01
As Experience increases by 1 unit, Wage is predicted to
increase by 0.43 units, holding Age and Education constant.
b.
What is the sample regression equation? (Negative value should
be indicated by a minus sign. Round your answers to 2 decimal
places.)
y-hat = + Education + Experience + Age
c.
What is the predicted value for Age = 38, Education = 3 and
Experience = 5. (Do not round intermediate calculations. Round
your answer to 2 decimal places.)
y-hat
29)
Suppose that the average IQ score is normally distributed with a
mean of 115 and a standard deviation of 11. In addition to
providing the answer, state the relevant Excel commands. (Use
Excel)
a.
What is the probability a randomly selected person will have an
IQ score of less than 89? (Round your answer to 4 decimal
places.)

41. Probability
b.
What is the probability that a randomly selected person will
have an IQ score greater than 125? (Round your answer to 4
decimal places.)
Probability
c.
What minimum IQ score does a person have to achieve to be in
the top 2.6% of IQ scores? (Round your answer to 2 decimal
places.)
Minimum IQ score
30)
Consider the following frequency distribution.
Class
Frequency
2 up to 4
15
4 up to 6
65
6 up to 8
75
8 up to 10
15
a.

42. Calculate the population mean. (Round your answer to 2
decimal places.)
Population mean
b.
Calculate the population variance and the population standard
deviation. (Round your intermediate calculations to 4 decimal
places and final answers to 2 decimal places.)
Population variance
Population standard deviation
31)
Acceptance sampling is an important quality control technique,
where a batch of data is tested to determine if the proportion of
units having a particular attribute exceeds a given percentage.
Suppose that 15% of produced items are known to be
nonconforming. Every week a batch of items is evaluated and
the production machines are adjusted if the proportion of
nonconforming items exceeds 19%. Use Table 1.
a.
What is the probability that the production machines will be
adjusted if the batch consists of 68 items? (Round intermediate
calculations to 4 decimal places, “z” value to 2 decimal places,
and final answer to 4 decimal places.)
Probability

43. b.
What is the probability that the production machines will be
adjusted if the batch consists of 136 items? (Round intermediate
calculations to 4 decimal places, “z” value to 2 decimal places,
and final answer to 4 decimal places.)
Probability
32)
Assume that X is a binomial random variable with n = 27 and p
= 0.92. Calculate the following probabilities. (Round your
intermediate and final answers to 4 decimal places.)
a.P(X = 26)
b.P(X = 25)
c.P(X ≥ 25)
33)
A social scientist would like to analyze the relationship between
educational attainment and salary. He collects the following
sample data, where Education refers to years of higher
education and Salary is the individual’s annual salary in
thousands of dollars:

44. Education
3
4
6
2
5
4
8
0
Salary
$39
48
62
47
75
53
107
50
Click here for the Excel Data File
a.
Find the sample regression equation for the model: Salary = β0
+ β1Education + ε. (Round intermediate calculations to 4
decimal places. Enter your answers in thousands rounded to 2
decimal places.)
+ Education
b.
Interpret the coefficient for education.

45. As Education increases by 1 unit, an individual’s annual salary
is predicted to increase by $7,000.
As Education increases by 1 unit, an individual’s annual salary
is predicted to increase by $8,000.
As Education increases by 1 unit, an individual’s annual salary
is predicted to decrease by $7,000.
As Education inceases by 1 unit, an individual’s annual salary is
predicted to decrease by $8,000.
c.
What is the predicted salary for an individual who completed 7
years of higher education? (Round intermediate coefficient
values to 2 decimal places and final answer, in dollars, to the
nearest whole number.)
$
34)
A sample of patients arriving at Overbrook Hospital’s
emergency room recorded the following body temperature
readings over the weekend:

46. 99.0
100.4
99.7
100.4
99.1
101.7
100.9
100.5
99.3
101.9
100.4
101.9
100.5
99.4
102.7
99.4
100.9
100.1
100.7
100.2
Click here for the Excel Data File
a.
Construct a stem-and-leaf diagram.
Stem
Leaf

47. b.
Interpret the stem-and-leaf diagram.
The distribution is symmetric.
The distribution is Positively Skewed.
The distribution is Negatively Skewed.
35)
A manager of a local retail store analyzes the relationship
between advertising and sales by reviewing the store’s data for
the previous six months.
Advertising (in $100s)
Sales (in $1,000s)
198
122
55
43
54
42
53
41
200
124
160

48. 130
Click here for the Excel Data File
a.
Calculate the mean of advertising and the mean of sales. (Round
your answers to 2 decimal places.)
Mean
Advertising
Sales
b.
Calculate the standard deviation of advertising and the standard
deviation of sales. (Round your answers to 2 decimal places.)
Standard Deviation
Advertising
Sales
c-1.
Calculate the covariance between advertising and sales. (Round
your answer to 2 decimal places.)
Covariance

49. c-2.
Interpret the covariance between advertising and sales.
Positive correlation
Negative correlation
No correlation
d-1.
Calculate the correlation coefficient between advertising and
sales. (Round your answer to 2 decimal places.)
Correlation coefficient
d-2.
Interpret the correlation coefficient between advertising and
sales.
Strong positive correlation
Weak negative correlation
Weak positive correlation
No correlation
Strong negative correlation

50. 36)
The monthly closing stock prices (rounded to the nearest dollar)
for Panera Bread Co. for the first six months of 2010 are
reported in the following table. Use Table 2.
Months
Closing Stock Price
January 2010
$200
February 2010
205
March 2010
208
April 2010
207
May 2010
209
June 2010
204
SOURCE: http://finance.yahoo.com.
a.
Calculate the sample mean and the sample standard deviation.
(Round intermediate calculations to 4 decimal places and
"sample mean" and "sample standard deviation" to 2 decimal
places.)
Sample mean
Sample standard deviation

51. b.
Compute the 90% confidence interval for the mean stock price
of Panera Bread Co., assuming that the stock price is normally
distributed. (Round "t" value to 3 decimal places, and final
answers to 2 decimal places.)
Confidence interval
to
c.
What happens to the margin of error if a higher confidence level
is used for the interval estimate?
The margin of error decreases as the confidence level increases.
The margin of error increases as the confidence level increases.
37)
Complete the following probability table. (Round Prior
Probability answers to 2 decimal places and intermediate
calculations and other answers to 4 decimal places.)
Prior
Probability
Conditional Probability
Joint
Probability
Posterior
Probability

52. P(B)
0.49
P(A | B)
0.10
P(A ∩ B )
P(B | A)
P(Bc)
P(A | Bc)
0.34
P(A ∩ Bc)
P(Bc | A)
Total
P(A)
Total
38)
A local restaurant is committed to providing its patrons with the
best dining experience possible. On a recent survey, the
restaurant asked patrons to rate the quality of their entrées. The
responses ranged from 1 to 5, where 1 indicated a disappointing
entrée and 5 indicated an exceptional entrée.
The results of the survey are as follows:

53. 5
2
5
3
5
5
1
2
4
5
4
5
4
1
5
4
5
5
5
5
4
2
3
5
4
2

54. 5
2
2
5
5
2
5
5
3
3
Click here for the Excel Data File
a.
Construct frequency and relative frequency distributions that
summarize the survey’s results. (Do not round intermediate
calculations. Round "relative frequency" to 3 decimal places.)
Rating
Frequency
Relative
Frequency
5
4
3
2
1

55. Total
b.
Are patrons generally satisfied with the quality of their entrées?
Yes
No
39)
At a new exhibit in the Museum of Science, people are asked to
choose between 71 or 200 random draws from a machine. The
machine is known to have 88 green balls and 82 red balls. After
each draw, the color of the ball is noted and the ball is put back
for the next draw. You win a prize if more than 58% of the
draws result in a green ball. Use Table 1.
a.
Calculate the probability of getting more than 58% green

56. balls.(Round intermediate calculations to 4 decimal places, “z”
value to 2 decimal places, and final answer to 4 decimal places.)
n
Probability
71
200
b.
Would you choose 71 or 200 draws for the game?
71 balls
200 balls
40)
A construction company in Naples, Florida, is struggling to sell
condominiums. In order to attract buyers, the company has
made numerous price reductions and better financing offers.
Although condominiums were once listed for $350,000, the
company believes that it will be able to get an average sale
price of $255,000. Let the price of these condominiums in the
next quarter be normally distributed with a standard deviation
of $17,000. Use Table 1.
a.
What is the probability that the condominium will sell at a price
(i) Below $231,000?, (ii) Above $293,000? (Round "z" value to
2 decimal places and final answer to 4 decimal places.)

57. Probability
Below $231,000
Above $293,000
b.
The company is also trying to sell an artist’s condo. Potential
buyers will find the unusual features of this condo either
pleasing or objectionable. The manager expects the average sale
price of this condo to be the same as others at $255,000, but
with a higher standard deviation of $21,000. What is the
probability that this condo will sell at a price (i) Below
$231,000?, (ii) Above $293,000? (Round your answers to 4
decimal places.)
Probability
Below $231,000
Above $293,000
41)
A random variable X is exponentially distributed with a mean of
0.17.
a-1.
What is the rate parameter λ? (Round your answer to 3 decimal
places.)
Rate parameter λ

58. a-2.
What is the standard deviation of X? (Round your answer to 3
decimal places.)
Standard deviation X
b.
Compute P(X > 0.30). (Round intermediate calculations to 4
decimal places and final answer to 4 decimal places.)
P(X > 0.30)
c.
Compute P(0.10 ≤ X ≤ 0.30). (Round intermediate calculations
to 4 decimal places and final answer to 4 decimal places.)
P(0.10 ≤ X ≤ 0.30)
42)
Professor Sanchez has been teaching Principles of Economics
for over 25 years. He uses the following scale for grading.
Grade
Numerical Score
Probability
A
4
0.140
B
3
0.200
C

59. 2
0.430
D
1
0.125
F
0
0.105
Part (a) omitted
b.
Convert the above probability distribution to a cumulative
probability distribution. (Round your answers to 3 decimal
places.)
Grade
P(X ≤ x)
F
D
C
B
A
c.
What is the probability of earning at least a B in Professor
Sanchez’s course? (Round your answer to 3 decimal places.)
Probability

60. d.
What is the probability of passing Professor Sanchez’s course?
(Round your answer to 3 decimal places.)
Probability
43)
The scheduled arrival time for a daily flight from Boston to
New York is 9:30 am. Historical data show that the arrival time
follows the continuous uniform distribution with an early
arrival time of 9:16 am and a late arrival time of 9:56 am.
a.
After converting the time data to a minute scale, calculate the
mean and the standard deviation for the distribution. (Round
your answers to 2 decimal places.)
Mean
minutes
Standard deviation
minutes
b.
What is the probability that a flight arrives late (later than 9:30
am)? (Do not round intermediate calculations. Round your
answer to 2 decimal places.)
Probability
44) Regression analysis can be used to analyze how a change in
one variable impacts the other variable, such as an increase in

61. marketing budget increasing sales. Find a unique area of your
life where one variable impacts the other variable (and that are
both measurable) and do a regression analysis on it. Be sure to
include the coefficient of determination as well as the test of
significance.
45)
Consider the following hypotheses:
H0: μ ≥ 201
HA: μ < 201
A sample of 80 observations results in a sample mean of 198.
The population standard deviation is known to be 20. Use Table
1.
a.
What is the critical value for the test with α = 0.05 and with α =
0.01? (Negative values should be indicated by a minus sign.
Round your answers to 2 decimal places.)
Critical Value
α = 0.05
α = 0.01
b-1.
Calculate the value of the test statistic. (Negative value should
be indicated by a minus sign. Round intermediate calculations
to 4 decimal places. Round your answer to 2 decimal places.)
Test statistic

62. b-2.
Does the above sample evidence enable us to reject the null
hypothesis at α = 0.05?
No since the value of the test statistic is not less than the
negative critical value.
Yes since the value of the test statistic is less than the negative
critical value.
Yes since the value of the test statistic is not less than the
negative critical value.
No since the value of the test statistic is less than the negative
critical value.
c.
Does the above sample evidence enable us to reject the null
hypothesis at α = 0.01?
No since the value of the test statistic is not less than the
negative critical value.
Yes since the value of the test statistic is less than the negative
critical value.
Yes since the value of the test statistic is not less than the
negative critical value.

63. No since the value of the test statistic is less than the negative
critical value.
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