Find the mean of the data set: 8, 12, 15, 10, 5.

Step 1: Recall the formula for the mean.

The mean is the sum of all data values divided by the number of values.

Mean = sum of values / number of values

Step 2: Add the data values.

8 + 12 + 15 + 10 + 5 = 50

Step 3: Count the number of values.

There are 5 values in the data set.

Step 4: Divide the sum by the number of values.

Mean = 50 / 5
Mean = 10

Therefore, the mean of the data set is 10.