How To Calculate Standard Deviation?

You can calculate standard deviation by addin the numbers of data that are together and dividing that number by the amount pieces of data.

THAT IS TOTALLY INCORRECT.

What was answered above was the calculation for getting an (mean) average.

If you take five numbers for example 1, 2, 3, 4, 5 then the (mean) average is 3.

But the standard deviation between them is 1.58814 and the variance is 2.5

Also the population std. deviation will be 1.41421 and the population variance will be 2.

see standard-deviation.appspot.com/