Raw moments can be defined as the arithmetic mean of various powers of deviations taken from origin. The rth Raw moment is denoted by μr’, r=1,2,3…. Then the first raw moments are given by
Central moments can be defined as the arithmetic mean of various powers of deviation taken from the mean of the distribution. The rth central moment is denoted by μr, r=1,2,3….
In general, given n observation x1, x2,…….xn the rth order raw moments (r=0,1,2,…) are defined as follows:
The first two moments of the distribution about the value 5 of the variable, are 2 and 20. Find the mean and the variance.