Degrees of Freedom
nSamples tend to underestimate the population data
nTo correct sampling error we subtract 2 from n
nAll scores are free to vary except 2 (e.g. when you know all but 1 data score then it is determined)
n s2 = Sample variance =  Sx2 =  SS =   35.00  = 11.67
n                         N-1    N-1      4 -1
n                       
n s = Sample standard deviation =  s2  = 11.67 = 3.42