A subscription service states that 62% of its customers renew each year. Sam takes a random sample of 28 customers and wishes to test, at the 10% significance level with a probability of at most 0.05 in each tail, whether the renewal proportion differs from 62%.
Find the critical region for Sam's test.
Find the actual significance level of a test based on this critical region.
In Sam's sample, 23 customers renew. State Sam's conclusion in context.
State one reason why a random sample is needed.