In a box-and-whisker plot, the interquartile range is a measure of the spread of the middle half of the data. Find the interquartile range for the data set: 10, 3, 7, 6, 9, 12, 13
In statistics, it is imperative to arrange your data entries from least to greatest. That would be the first step of our solution
3 6 7 9 10 12 13
Interquartile range is the difference of the last quartile to the first quartile. Divide your entire data set into four parts. Each division is called a quartile. Its numerical value is the average of its numbers. However, since our data set contains 7 numbers, which is odd, we write the median (middle value) twice. The quartiles are: