Variance is calculated by taking the differences between each number in the set and the mean, squaring the differences (to make them positive) and dividing the sum of the squares by the number of values in the set. We do as follows:
Mean = 8+10+14+12 / 4 = 11
Variance = (8-11)^2 + (10-11)^2 + (12-11)^2 + (14-11)^2 / 4
Variance = 5 <-------OPTION C
