Based on the box plot below, the answer to his question is 23 minutes. To calculate the IQR, you must subtract the value of the first quartile from the value of the third quartile (IQR = Q3 – Q1).

Quartiles are the values that divide a data set into quarters: Put the values in order Divide the list into four equal parts The Quartiles are at the divisions The interquartile range shows the ...