1. IUBAT–INTERNATIONAL UNIVERSITY OF BUSINESS AGRICULTURE AND TECHNOLOGY
Midterm examination
STA 240 Set: X
Full marks: 20 Time: 50 minutes
1. Let X=fertilizer, Y=production of rice.
X Y
1 2
2 5
3 8
a) Find the correlation coefficient, r.
(1.5)
b) Interpret the result.
(1)
c) Fit a regression line between X and Y.
(2)
d) Interpret the results.
(2)
e) When X=10, what will be the value of Y?
(0.5)
2. Two coins are tossed, find the probability that two heads are
obtained. (1.5)
3. f(x)=x5 ; 0<x<1

2. A) Find E(X).
(1)
B) Also find V(X).
(2)
4. Explain the concept of lottery method with an example.
(2)
5. What is the probability of choosing a day from a month?
(1.5)
Md. Mortuza Ahmmed