In the above frequency distribution, the frequencies are asymmetrical. So, to find skewness use:
K.P.C.S = 3(x-m/σ)
Here x̄ = (∑fx/N)
Median after finding less than cumulative frequency (L.C.F)
M = (N+1/2)th item; and
Karl Pearson's coefficient of skewness:
Note: Same type of problems can also be solved for continuous data.