Question

Determine whether the range or interquartile range best describes the spread of a dataset.

The times (in seconds) for a high school boys’ 100-meter race:

11.0 11.2 11.7 12.2 12.4 12.6 12.8 12.9 13.1 13.3 13.8 14.2 14.3 14.3 16.5 17.6 18.0

(1 point)
Responses

Range; the distribution is symmetrical, or close to it, and there aren’t any outliers in the dataset.
Range; the distribution is symmetrical, or close to it, and there aren’t any outliers in the dataset.

IQR; the distribution is skewed, and there are outliers in the dataset.
IQR; the distribution is skewed, and there are outliers in the dataset.

IQR; the distribution is symmetrical, or close to it, and there aren’t any outliers in the dataset.
IQR; the distribution is symmetrical, or close to it, and there aren’t any outliers in the dataset.

Range; the distribution is skewed, and there are outliers in the dataset.

Answer 1

IQR; the distribution is skewed, and there are outliers in the dataset.

Reason: n = 17, median = 13.1, Q1 = 12.3, Q3 = 14.3 so IQR = 2.0. Upper fence = Q3 + 1.5·IQR = 14.3 + 3.0 = 17.3, so 17.6 and 18.0 are outliers. The right skew and outliers make the IQR the better spread measure.