Question

Let y=5x_1+3x_2+〖9x〗_3 find Mean and variance of y. Where x_1,x_2 and〖 x〗_3 are independent uniform random variable with parameter of x_(1 ) as [2:4] for x_2 as [5:10] and for x_3 as [0:4]?

Answer 1

Mean value = 55.5

Explanation:

Y = 5X1 + 3X2 + 9X3

CASE 1:

X1 = 2, X2 = 5, X3 = 0

Y = 5(2) +3(5) + 9(0) = 10 + 15 + 0 = 25

CASE 2:

X1 = 4, X2 = 10, X3 = 4

Y = 5(4) + 3(10) + 9(4) = 20+30+36 = 86

The mean value of Y is (25 + 86)/2 = 55.5

The variance from the mean is 30.5