Question: Compute and interpret a range, interquartile range, and semiinterquartile range.
• The range is the difference between the largest value (L) and smallest value (S) in a data set. Although the range provides a simple measure for variability, it accounts for only two values (the largest value and smallest value) in a distribution.
• The interquartile range (IQR) is the range of a distribution of scores after the top and bottom 25% of scores in that distribution are removed.
The quartiles split a data set into four equal parts, each containing 25% of the data. The 25th percentile is called the lower quartile, the 50th percentile is called the median quartile, and the 75th percentile is called the upper quartile.