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.(adsbygoogle = window.adsbygoogle || []).push({});

(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.

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# Finding mean of Y if Y=(X1+X2+X3)/3 given mean and variance of x's

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