A company claims that 20% of customers choose a premium service. A researcher tests H0:p=0.2H_0:p=0.2H0:p=0.2 against H1:p>0.2 H_1:p>0.2\,H1:p>0.2 using 40 customers and the critical region X≥13X\geq13X≥13.
Interpret a Type I error in context.
Interpret a Type II error if the true proportion is 0.35.
Calculate both error probabilities.
8 exam-style questions on WJEC A Level Maths 2.5.4 Statistical hypothesis testing. Each one has a worked solution and a mark scheme showing where the marks go.