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.
40 exam-style questions on WJEC A Level Maths 2.5 Statistical hypothesis testing, covering 2.5.1 Statistical hypothesis testing, 2.5.2 Statistical hypothesis testing, 2.5.3 Statistical hypothesis testing, 2.5.4 Statistical hypothesis testing, and 2.5 Statistical hypothesis testing. Each one has a worked solution and a mark scheme showing where the marks go.