1. Ch2.7_DataMeasuresCentralTendency.notebook September 19, 2011
Warm Up
y
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Graph 5
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y < x 4 6 5 4 3 2 1
2
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0 1 2 3 4 5 6
x
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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) =
4
