What is the variance of the following numbers?: 11, 23, 45, 42, 39, 56, 51, 17, 22, 29, 46, 33, 38, 33, 31,
Assuming we are looking for a population variance:
Here is the data in a spreadsheet format (of course, with the given data, there are spreadsheet or calculator functions to give the variance without the intermediate values; they are here for instructional purposes only).
The Population Variance is
(the sum of the squares of the differences of the individual data values from the mean)
(the number of data values)
Not that if the data was intended to be only a sample from some larger population then you should calculate the "Sample Variance" for which the division is by (one less than the number of data values).