Referring to question 43, find the power of a 5 % level test when the true population mean time for headache relief is 35 min.

Question 43

An aspirin manufacturer claims that its aspirin stops headaches in less than 30 min. A random sample of 100 people who use the pain killer finds that the average time it takes to stop a headache is 28.6 min with a sample standard deviation of 4.2 min. Test, at the 5 % level of significance, the manufacturer’s claim that this product stops headaches in less than 30 min.