Homework SourseA random variable takes values 1234 with prob 003 030 028 03
A random variable takes values 1,2,3,4 with prob 0.03, 0,30, 0.28, 0.39 what is the variance?
A random variable takes values 1,2,3,4 with prob 0.03, 0,30, 0.28, 0.39 what is the variance?
Solution
Variance = E(X^2) - E(X)^2
E(X) = 1*0.03 + 2*0.30 + 3*0.28 + 4*0.39 = 3.03
E(X^2) = 1*0.03 + 4*0.30 + 9*0.28 + 16*0.39 = 9.99
Variance = 9.99 - ( 3.03)^2 = 0.8091 Answer
