d ). Let X1, X2, . . . An- Nce, as ?) be a random sample from a normal distribution with bown variance. The margin of error for a 98 % confidence interval for u is greater when n= 87 than when n= 23 e ). A criminal trial in US. can be formulated as a hypothesis test with Hi: The defendant is not guilty and HA: the defendant is guilty. In the framework, rendering a guilty verdict when the defendant is not quilty is a type I errorQ . 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