How do I get the answer to this

Question

Find the sample variance of the following data (build the table). 21, 38, 40, 14, 25, 18

Answer 1

The first column is the list of values. From that, calculate the mean.

The second column is the data value minus the mean.

The third column is the square of the second column.

Add up the third column and divide by n - 1 (in this case, since n = 6, that would be 5. That number is the answer.