REHS/EPH Program Week Five Practice Test

The measure being described is the interquartile range. It is calculated by subtracting the first quartile (Q1) from the third quartile (Q3), which captures the spread of the middle 50% of the data. This focus on the central portion makes it less sensitive to extreme values than measures that use the full data range. In contrast, the range uses only the extreme values (max minus min) and can be greatly affected by outliers. Variance and standard deviation involve all data points and the mean, measuring average squared deviations and their square root, which can also be influenced by outliers, though in different ways. To compute the interquartile range, order the data, find Q1 and Q3, and take their difference.