first, we find the mean (average)...
(8 + 10 + 14 + 4) / 4 = 36/4 = 9
now subtract the mean (9) from every number in the data....then square it.
8 - 9 = -1...-1^2 = 1
10 - 9 = 1...1^2 = 1
14 - 9 = 5....5^2 = 25
4 - 9 = -5...-5^2 = 25
now take the mean of ur results
(1 + 1 + 25 + 25)/4 = 52/4 = 13 <== this is ur variance...and if u wanted to find the standard deviation, u would just take the square root of 13.
