Use statistics and probability, show all processes,many thanks

Please do not copy other's answers if you cannot work out this question??

For each statement below, write down whether it is true or false and provide a justification.

Statement 7. The Best Linear Unbiased Estimator must have variance equal to the Cramer Rao lower bound. Statement 8. Let (X1, X2, ..., X\") be a random sample from the standard normal distribution and let Yn = Xn where X" = n'1 221:1 Xi. Then Yn2 follows a x? distribution. Statement 9. The set of values of 30 which are rejected by a size a hypothesis test of H0 : 6 = 60 and H1 : 9 7E (90 forms a 1 a condence interval for 0. Statement 10. If (T1,T2) is a 1 a: condence interval for I9 then (g(T1), 9(T2D is a 1 a condence interval for 9(6) for any function g(-)