A wine producer claims that the proportion of its customers who cannot distinguish its product from frozen grape juice is at most 0.09. The producer decides to test this null hypothesis against the alternative that the true proportion is more than 0.09. The decision rule adopted is to reject the null hypothesis if the sample proportion of people who cannot distinguish between these two flavors exceed 0.14.
a) If a random sample of 400 customers is selected, what is the probability of Type I error using this decision rule?
b) Suppose that the true proportion of customers who cannot distinguish between these flavors is 0.20. If a random sample of 100 customers is selected, what is the probability of a type II error?