Q . a ) For a random sample Y, Y2, Y's... Ynn Exp (7) from an exponential distribution with rate 1 , the maximum likelihood estimator for A is 1 = 3 ri = ( ) . For large n, the sampling distribution of A is approximately normal b ) The sample variance for a normal random sample is an unbiased estimator of the true variance. ( ) If it obtain 95 % confidence intervals for different parameters in each of loo independent experiments . 5 of those confidence intervals will not contain the true parameter value, on average