Which measure of variability-range or IQR-best describes the spread of the dataset?
Social studies group project grades (out of 100) for Mr. Chang's first period class
85 88 90 90 92 92 95 96 99
1 answer
The range would be a better measure of variability in this dataset, as it gives the difference between the highest and lowest values (99-85=14), and indicates the spread of the grades. The IQR would not be as informative in this case, as the dataset is relatively small and the middle 50% of the scores are not significantly different from the overall range.