The box plots below show the average gas mileage, in miles per gallon, of the cars sold at a dealership in June and in December.

Gas Mileage of Cars Sold in June:
- Whiskers range from 21 to 33.
- Box ranges from 22 to 29.
- Line divides the box at 24.

Gas Mileage of Cars Sold in December:
- Whiskers range from 14 to 26.
- Box ranges from 18 to 21.
- Line divides the box at 19.

The manager used the table below to compare the measures of center and the measures of variability.

| | Median | Range | Interquartile Range |
|---|---|---|---|
| Sold in June | 24 | 33 minus 21 = 12 | 29 minus 22 = 7 |
| Sold in December | 19 | 26 minus 14 = 12 | 21 minus 16 = 5 |

What error did the manager make in the table?

A. The median for June should be 22.
B. The median for December should be 14.
C. The interquartile range for December should be 21 minus 18 = 3.
D. The interquartile range for December should be 26 minus 18 = 8.

In Mathematics and Statistics, IQR is an abbreviation for interquartile range and it can be defined as a measure of the middle 50% of data values when they are ordered from lowest to highest.

Mathematically, interquartile range (IQR) of a data set is the difference between third quartile and the first quartile :

Interquartile range (IQR) of data set = third quartile - first quartile

Interquartile range (IQR) of Gas Mileage of Cars Sold in December = 21 - 18

Interquartile range (IQR) of Gas Mileage of Cars Sold in December = 3.

Complete Question

The box plots below show the average gas mileage, in miles per gallon, of the cars sold at a dealership in June and in December.

The manager used the table below to compare the measures of center and the measures of variability.

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 minus 18 = 3.

The interquartile range for December should be 26 minus 18 = 8.