※ 引述《alanfirst ()》之銘言： : 3. Suppose we plan to select a random sample from a normal distribution : known to have a standard deviation of 8. We know that the population mean is : either 42 or 50, and we wish to test Ho:u=42 against H1=50 determine the sample : size n and a critical region such that α=0.05 and B=0.1 _ Suppose we have X1,.....Xn,from LR-test we know Xn is our test statistic, and the critical region can be define using the relation that α=0.05 _ Xn-42 => P( -------> c )=0.05 => c=(8/n)*Z0.05+42 --------(A) 8/n next, we use B=0.1 to determine the sample size n _ Xn-50 c-50 c-50 => P( --------- < ---------)=0.1 => ---------=-Z0.1 -------(B) 8/n 8/n 8/n using formula A and B, we can solve the problem. --

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