Standard Deviation normalization of data in data mining

Data Normalization with the Help Of Standard Deviation

Data is in attribute tuples and data can be normalized by using standard deviation.

Example:

Age
22
40

First Step:

Calculate the mean of the data:

Mean = (22+40) / 2 = 22

Second Step:

Now, we will subtract the mean from all the values and find the square of all data :

(22-22)^2 = 0
(40-22)^2 = 324

[quads id=1] Third Step:

Now, we will find the deviation as follows:

Deviation = sqrt ((0 + 324 / 2) = 162

Fourth Step:

Now we will normalize the attribute values:

(x – Mean) / Deviation

For 22 : (22 – 22) / 162 = 0

For 40 : (40 – 22) / 162 = 0.11

Age before normalization Age after normalization
22 0
40 0.11