Find the mean absolute deviation by finding the sum of the absolute value of x minus mu, all divided by N. In this formula, mu is the mean, x is the value of the term and N is the total number of terms.
- Find the mean
For the given set of values, find the mean by summing all of the values together and dividing by the total number of terms. For example, a set with the three number 5, 7 and 3 has a mean of (5 + 7 + 3)/3 = 5. Set this value to the Greek letter mu.
- Find the absolute value of x minus mu
Subtract each term in the series, represented by the variable x, by mu, the mean of all values in the series. Then, take the absolute value of that number. For example, in the set 5, 7 and 3 with a mean of 5, the absolute value of the terms are 0, 2 and 2 respectively.
- Sum all values of the absolute value of x minus mu
After determining the absolute value of each term minus the mean, add all of the found values together.
- Divide by N
Divide the sum of the absolute values by the total number of values in the series to find the mean absolute deviation.