Find the variance of 101, 102, 100, 100, 110, 109, 109, 108, 109

101, 102, 100, 100, 110, 109, 109,108, 109 average to 105.3

subtracting the mean from each number yields the below-

-4,-3,-5,-5,5,4,4,3,4

Squaring each number gives-

16,9,25,25,16,16,9,16

The average of these numbers is 12.89 to two decimal places, so your variance is 12.89