Y_1,Y_2, . . . ,Y_n are independent and identically distributed Exp(Q)

random variables.

Which are the distribution of the sample mean?

Sample mean=X=(1/n)*SIGMA(Y_k)

1. X~Exp(Q)

2. X~Exp(nQ)

3. X~Exp(Q/n)

4. X~Gamma(n,Q)

5. X~Gamma(n,(Q/n))

(Bow)