Coefficient Of Kurtosis Formula. S sample standard deviation. 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.
Of course theaverage value of zis always zero but the average value ofz4is always 1 and is larger when you have afew big deviations on either side of the mean than when you have a lotof small ones. Calculate kurtosis in excel. 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.
Pearson s coefficient of skewness γ 1 β 1 kurtosis kurtosis refers to the degree of peakedness of a frequency curve.
Calculate kurtosis in excel. For a very large sample very high n the differences between and among n 1 n n 1 n 2 and n 3 are becoming negligible and the sample kurtosis formula approximately equals. A normal curve has a value of 3 a leptokurtic has beta 2 greater than 3 and platykurtic has beta 2 less then 3. μ4 x ˉx 4 n.
