Question

Hi, Statistics problem

Var (X)=2,if U=5x+2,then Var (U) is Equal to

I know that the correct answer is equal to 50, I just need to know how :D >3 help please

Answer 1

Var(U) = 50

Explanation:

The properties of variance will be used here

Given

Var(X) = 2

U = 5x+2

We can see that the variable x is multiplied with an integer

Using the property of variance

Var(aX) = a^2 Var(x)

So,

Var(U) = 5^2 Var(x) = 25*2 = 50

For the +2, if the same number is added to all the values of variable there is no change in variance i.e.

Var(X+2) = Var(X)

Hence, the value of Var (U) is 50 ..