How do you calculate mean absolute deviation?

Answer 1

The Mean Absolute Deviation is calculated in three simple steps.

1) Determine the Mean: Add all numbers and divide by the count

example: the weights of the following three people, denoted by letters are

A - 56 Kgs

B - 78 Kgs

C - 90 Kgs

Mean = (56+78+90)/3

= 74.6

2) Determine deviation of each variable from the Mean

i.e 56-74.6 = -18.67

78-74.6= 3.33

90-74.6 =15.33

3) Make the deviation 'absolute' by squaring and determining the roots i.e eliminate the negative aspect

Thus the Mean Absolute Deviation is (18.67 +3.33+15.33)/3 =12.44

Alternatively , you can use the excel formula =AVEDEV(56,78,90) to obtain the result.

Different Methods

There are different formulas for the calculation of mean absolute deviation. For example mean absolute deviation from mean and mean absolute deviation from median. Similarly the formulas for grouped and ungrouped data are also different. In order to see the calculation of mean absolute deviation from mean and mean absolute deviation from median for both grouped and ungrouped data please visit the link given below.

Let's consider the sample {2, 2, 3, 4, 14}.

First of all you must decide, what am I calculating the mean absolute deviation from? Will it be the mean, the mode or the median? (It could be any measure of what statisticians call 'location' or 'central tendency'.)

For no good reason except that it's familiar to most people let me choose the mean of the sample. It proves to be 5.

Now we need the absolute deviation of each sample element from the mean. Notice that these are the distances between the mean and the sample elements.

|2 - 5| = |-3| = 3

|2 - 5| = |-3| = 3

|3 - 5| = |-2| = 2

|4 - 5| = |-1| = 1

|14 - 5| = |9| = 9

The sum of these is 18; then their average is 18/5 = 3.6. So the mean absolute deviation (from the mean) is 3.6. In other words, the sample points are, on average 3.6 units from the mean.

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Answer 2

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Answer 3

how to do the calculation of the mean absolute

deviation