Question

Maria surveyed girls on the amount (in $) they spent on a dress for the middle school spring fling:
79, 79, 79, 82, 84, 85, 89, 90, 99, 100, 100, 100, 129, 139, 155, 174, 189, 200, 209, 250
Which measure of variability—IQR or MAD—best describes the spread of the dataset?
(1 point)
MAD; the data distribution is symmetrical
IQR; the data distribution is symmetrical
MAD; the data distribution has outliers
IQR; the data distribution is skewed

Answer 1

IQR; the data distribution is skewed.

Reason: the mean (≈125.6) is noticeably above the median (100) due to high values (e.g., 209, 250), so the distribution is right-skewed and has high outliers. IQR is a resistant measure better for skewed/outlier-prone data than MAD (which uses the mean and is affected by outliers).