In this worksheet, we will learn how to find the mean from an assumed mean.
Example
Find the mean of 10 numbers.
50.5, 50.7, 52.1, 53.5, 54.0, 56.9, 58.8, 59.1, 59.3, 59.8
Method
First take a guess at what the mean could be, 54.0 perhaps.
Then work out the deviations of each value from 54.0
50.5 - 54.0 = -3.5
50.7 - 54.0 = -3.3
52.1 - 54.0 = -1.9
53.5 - 54.0 = -0.5
54.0 - 54.0 = 0
56.9 - 54.0 = 2.9
58.8 - 54.0 = 4.8
59.1 - 54.0 = 5.1
59.3 - 54.0 = 5.3
59.8 - 54.0 = 5.8
Add the deviations to get 14.7
Share the deviations among the 10 values 14.7 ÷ 10 = 1.47
Add this on to the assumed mean.
Mean = 54.0 + 1.47 = 55.47