1. Ch2.7_DataMeasuresCentralTendency.notebook September 19, 2011
Warm Up
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Chapter 2.7
Data and Measures of Central Tendency
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2. Ch2.7_DataMeasuresCentralTendency.notebook September 19, 2011
Vocab
Statistics ­ the study of data
Population ­ large (huuuuuuuuge) group of data
Sample ­ smaller group from the population
Frequency Table
A way to compile and organize data
# of pets
Frequency
at home
0
1
2
3 or more
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3. Ch2.7_DataMeasuresCentralTendency.notebook September 19, 2011
Fill in the Frequency Table with the
the given test scores in red
Score Interval Frequency
90 83 68
90 ­ 100
34 85 76
80 ­ 89 79 89 80
70 ­ 79 77 59 91
81 72 64
60 ­ 69
98 96 62
50 ­ 59
49 or lower
Measures of Central Tendency
Mean ­ average of data
Median ­ middle number (when arranged in order)
Mode ­ most frequent value
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4. Ch2.7_DataMeasuresCentralTendency.notebook September 19, 2011
Example
Find the mean, median, and mode of the following fourteen
numbers
4, 6, 2, 8, 9, 4, 6, 4, 5, 7, 5, 8, 3, 2
Mean (average) =
Sum of numbers
14
Median (middle #) =
2, 2, 3, 4, 4, 4, 5, 5, 6, 6, 7, 8, 8, 9
Mode (most common) =
Example
Find the mean, median, and mode of the following ACT scores
22, 28, 30, 27, 25, 31, 25, 26, 19
Mean (average) =
Median (middle #) =
Mode (most common) =
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5. Ch2.7_DataMeasuresCentralTendency.notebook September 19, 2011
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