You can calculate the mean of a data set by adding up all of the numbers and dividing them by the number of values in the set.
For instance, the image provided contains the following data values: 85, 97, 84, 88, 95, 100, and 81.
The first step of finding the mean is to add up all of the numbers. 85 + 97 + 84 + 88 + 95 + 100 + 81 = 630
The next (and final) step of finding the mean is to count the total amount of numbers in the data set and divide that by the sum (630). 85 (1), 97 (2), 84 (3), 88 (4), 95 (5), 100 (6), 81 (7) 630 ÷ 7 = 90
