Question

What is the variance of z=2x+3y, in terms of the variances of x and y?

Answer 1

V(z) = V(2x + 3y) = `2^2` `xx` V(x) + `3^2` `xx` V(y) = 4V(x) + 9V(y)

Explanation:

V[ax + by] = `a^2` V(x)+ `b^2` V(y) is the formula employed.