Question

gas mileage of cars sold in december
the manager used the table below to compare the measures of center and the measures of variability.

	median	range	interquartile range
sold in december	19	26 - 14 = 12	21 - 16 = 5

what error did the manager make in the table?
the median for june should be 22.
the median for december should be 14.
the interquartile range for december should be 21 - 18 = 3.
the interquartile range for december should be 26 - 18 = 8.

Explanation:

Step1: Recall inter - quartile range definition

The inter - quartile range (IQR) is the difference between the third quartile ($Q_3$) and the first quartile ($Q_1$). For the box - and - whisker plot of cars sold in December, the first quartile ($Q_1$) is 18 and the third quartile ($Q_3$) is 21.

Step2: Calculate correct IQR for December

$IQR = Q_3−Q_1=21 - 18=3$
The manager incorrectly calculated the inter - quartile range for December.

Answer:

The interquartile range for December should be 21 - 18 = 3.