The random variable X has expectation 13 and variance 4, while Y has expectation 20 and
variance 2. If X and Y are independent, the expectation and variance of (X + Y )/2 are
respectively
(a) 16.5 and 1.5 (b) 18 and 2 (c) 19.3 and 1.66 (d) 17.4 and 3.08 (e) none of these
The answer is (a), but im not sure how to get the answer,
i tried to use the following properties E(Y) aE(X) + b and var(Y) = a^2var(X)
but im not sure where to go from just pluging in the values?
please help
variance 2. If X and Y are independent, the expectation and variance of (X + Y )/2 are
respectively
(a) 16.5 and 1.5 (b) 18 and 2 (c) 19.3 and 1.66 (d) 17.4 and 3.08 (e) none of these
The answer is (a), but im not sure how to get the answer,
i tried to use the following properties E(Y) aE(X) + b and var(Y) = a^2var(X)
but im not sure where to go from just pluging in the values?
please help