AP Statistics : Univariate Data Descriptors
Study concepts, example questions & explanations for AP Statistics
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Example Questions
Example Question #2 : How To Use Boxplots To Summarize A Data Set
Which data set would be represented by this boxplot?
A boxplot indicates the quartiles of the data set. In this case we can see that the median or second quartile is 15. We can immediately eliminate
Now we need to find the data set with the correct first and third quartile. The boxplot indicates that our first quartile is 10.5. We can find Q1 by finding the median of the lower half, not including the median:
Example Question #41 : Univariate Data
Which statement about the data represented by this boxplot is not true?
The range is exactly twice the interquartile range.
The interquartile range is 10.
The median is 15.
The third quartile is 9.
The third quartile is 9.
In order to get this question right, we need to be able to distinguish between the first and the third quartile.
The third quartile, 19, is the median of the upper half of the data.
The first quartile, 9, is the median of the lower half of the data.
This means that the "correct" wrong statement is "the third quartile is 9," since 9 is the first quartile.
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