How to calculate standard deviation given mean and sample size?

In addition to mean and sample size you will need the individual scores.

The formula for standard deviation is:

S^2 = E (X-M) ^2/N-1

Here's an example:

Data set: 4,4,3,1

Mean: 3

Sample size: 4

First, put the individual scores one after the other and subtract the mean from it.

4 - 3 = 1

4 - 3 = 1

3 - 3 = 0

1 - 3 = - 2

Second, square the answers you got from step 1.

1^2 = 1

1^2 = 1

0^2 = 0

-2^2 = 4

Third, plug the values from step 2 into the formula.

S^2 = (1+1+0+4) / (4-1) = 6/3 = 2

Standard deviation = 2