Tuesday, December 18, 2007

The Range of a Set of Data

Problem: Cheryl took 7 math tests in one marking period. What is the range of her test scores?   [IMAGE]

89, 73, 84, 91, 87, 77, 94
Solution: Ordering the test scores from least to greatest, we get:

73, 77, 84, 87, 89, 91, 94

highest - lowest = 94 - 73 = 21
Answer: The range of these test scores is 21 points.
Definition: The range of a set of data is the difference between the highest and lowest values in the set.

In the problem above, the set of data consists of 7 test scores. We ordered the data from least to greatest before finding the range. We recommend that you do this, too. This is especially important with large sets of data.