Let X1, X2, X3 be three random variables. Suppose all three have mean μ and variance 1. The sample mean is Y = (X1 +X2 +X3)/3. (a) Can you compute the mean of Y? If so, what is it? If not, why not? I have that it is either μ OR that it is not possible to find, since we don't know if they are independent or not (as it says later in the question). I have a strong feeling that it is the latter, but I am not sure. (b) If we assume that the three random variables are independent, what would the variance of Y be? 1/3 right? Just to be sure.