Question

S.D(X) = 6 and S.D(Y) = 8. If X and Yare independent random variables, then S.D(X-Y) is:

Answer 1

14

Step-by-step explanation:

For independent variables X and Y;

S.D(X - Y) is expanded as :

S.D(X) + S.D(Y)

If S.D(X) = 6 and S.D(Y) = 8 ; where, X and Y are independent ;

SD(X-Y) = SD(X) + SD(Y)

SD(X - Y) = 6 + 8

SD(X - Y) = 14