These data show the ring size for a sample of 8 men 12 10 11.5,11.5, 12, 9, 9, 11 what is the best approximation of the standard deviation of the ring size data

Given the data above N=8

mean is (12+10+11.5+11.5+12+9+9+11) / 8

thus, mean = 10.75

Sample standard, s = √ (∑ (x-m) ²) / (n-1)

= 1.172

I therefore, believe that the best approximation of standard deviation is 1.17