QUESTION: A company sells packets of biscuits that they claim, on average, contains at least 20 g biscuits in each packet. They admit that their claim is wrong (and will refund any money) if a sample of 40 has a mean less than 19.8 g. If the standard deviation is 0.5 g,
a) Formulate the appropriate null and alternative hypotheses, and determine the type of test.
b) If the test is conducted at α = 0.05, determine the critical value that specify the rejection region, then complete this sentence: Reject H¬0 if test statistic is ___________________
c) Find the probability of a Type I error.
d) Find the probability of a Type II error and determine the power of test if the true mean is 19.5 g.