A simple random sample of 25 observations will be taken from a population that is assumed...

A simple random sample of 25 observations will be taken from a population that is assumed to be normal with a standard deviation of 37. We would like to test the alternative hypothesis that the standard deviation is actually more than 37. If the sample standard deviation is 40 or more, then the null hypothesis will be rejected (this called a decision rule).
1. What significance level would this decision rule cause?
2. If the population standard deviation is really 42, what is the probability of a type II error under this decision rule?
3. If the population standard deviation is really 42, what sample size is needed to make the power of the test at least 90%?

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orchestra answered 1 year ago

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