A restaurant's records indicate that 30% of customers order a starter. The manager believes that the population proportion has decreased. A random sample of 40 customers is taken and X X\,X is the number who order a starter.
Find the critical region for a test at the 5% level of significance.
Find the actual significance level.
In the sample, 7 customers order a starter. Complete the hypothesis test.
Explain why the actual significance level is not exactly 5%.
209 exam-style questions on CCEA A Level Maths 4.6 Statistical hypothesis testing (A-level only), covering 4.6.1 Statistical hypothesis testing (A-level only), 4.6.2 Statistical hypothesis testing (A-level only), 4.6.3 Statistical hypothesis testing (A-level only), 4.6.4 Statistical hypothesis testing (A-level only), and 4.6.5 Statistical hypothesis testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.