Consider the following discrete probability distribution X P

Consider the following discrete probability distribution. X P(X) 0 0.2 1 0.3 2 0.4 3 0.1 Total 1

Calculate the mean of the distribution.

Calculate the variance of the distribution.

Solution

MEAN = X1*P(X1)+.....XN*P(XN)

MEAN = 0*0.2+1*0.3+2*0.4+3*0.1 = 1.4

VARIANCE =

we will use the following formula:

^2=x^2*p(x)^2 = 2.8 - 1.4^2 = 0.84