Mrs. Little creates a boxplot for the test scores on her latest math test. She finds that the interquartile range is 20 points. What does this mean?

Mrs. Little creates a boxplot for the test scores on her latest math test. She finds that the interquartile range is 20 points. What does this mean?

I searched Google under the key words "interquartile range" to get these possible sources:

http://www.google.com/search?client=safari&rls=en&q=interquartile+range&ie=UTF-8&oe=UTF-8

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

The interquartile range (IQR) in a boxplot represents the spread or dispersion of the middle 50% of data values. It is calculated by finding the difference between the upper quartile (Q3) and the lower quartile (Q1). In this case, since the IQR is 20 points, it means that the range between the scores of the 25th percentile and the 75th percentile is 20 points.

To find the interquartile range, Mrs. Little would have first needed to determine the lower quartile (Q1) and the upper quartile (Q3) of the test scores. These quartiles are calculated by dividing the data into four sections, with each section representing 25% of the scores. The lower quartile (Q1) is the median of the lower half of the data, and the upper quartile (Q3) is the median of the upper half of the data.

Once she found the values for Q1 and Q3, she could subtract Q1 from Q3 to find the interquartile range. In this case, the IQR is 20 points, indicating that the middle 50% of scores on the math test have a range of 20 points.