Compute the mean and variance of the following discrete prob

Compute the mean and variance of the following discrete probability distribution.

x

P(x)

2

.50

8

.30

10

.20

Solution

1. Mean = probability*value = 2*0.5+8*0.3+10*.2
= 1+2.4+2= 5.4
2. Variance = (value-mean)^2/total population= (5*(2-5.4)^2+3*(8-5.4)^2+2*(10-5.4)^2)/10
=> 12.04