What is the sample varience (correct to the 4th decimal)?

Question

The statistics Education mark (given as percentage) of 50 students in the math module were:35;53;44;79;76;58;65;54;53;39;54;44;52;47;95;77;51;45;69;72;36;82;33;50;87;52;69;70;47;52;80;90;64;69;45;38;52;67;78;92;56;55;77;45;78;45;66;72;87;60

Answer 1

To find the SD, first find the mean, m, by summing the data and dividing by 50. The mean is 61.12.

For each datum X calculate (X-m)² and add up all these (∑(X-m)²) then divide by 50. This is the population variance. To find the sample variance we divide by 49 instead of 50. We get sample variance=271.1282.