Question

The test scores for a math class are shown below.

81, 84, 82, 93, 81, 85, 95, 89, 86, 94
What are the mean, median, and mode of the data set?

A. mean: 87.5; median: 85.5; mode: 81
B. mean: 87; median: 85.5; mode: 81
C. mean: 85.5; median: 87; mode: 81
D. mean: 87.2; median: 85; mode: 81

Answer 1

To find the mean, add up all the numbers and divide by how many numbers there are:

(81 + 84 + 82 + 93 + 81 + 85 + 95 + 89 + 86 + 94) / 10 = 876 / 10 = 87.6

The mean is 87.6.

To find the median, first reorder the numbers from least to greatest:

81, 81, 82, 84, 85, 86, 89, 93, 94, 95

Since there are an even number of values, the median is the average of the two middle numbers:

(85 + 86) / 2 = 85.5

The median is 85.5.

To find the mode, we look for the number that appears most frequently. In this case, 81 appears twice and all other numbers appear only once. Therefore, the mode is 81.

Therefore, the correct option is:

A. mean: 87.6; median: 85.5; mode: 81