Kurtosis Formula For Ungrouped Data. X i is the ith sample. S 2 sample variance.
S 2 sample variance. Kurtosis pertains to the extremities and not to the center of a distribution. The third formula below can be found in sheskin 2000 and is used by spss and sas proc means when specifying the option vardef df or by default if the vardef option is omitted.
The mean of x is denoted by x and is given by x 1 n i 1 n x i.
G frac sum i 1 n left x i bar x right 3 n 1 s 3 where bar x is the sample mean. The third formula below can be found in sheskin 2000 and is used by spss and sas proc means when specifying the option vardef df or by default if the vardef option is omitted. The only difference between formula 1 and formula 2 is the 3 in formula 1. Therefore sample kurtosis equals.
