The probability that a customer who receives a promotional email makes a purchase is 0.25. Priya believes that using a new email subject line will increase the proportion of customers who make a purchase.
After using the new subject line, a sample of 120 customers is taken and 40 make a purchase.
Stating your hypotheses clearly test, at the 5% level of significance, whether or not there is evidence to support Priya's belief.
33 exam-style questions on Edexcel AS Level Maths Hypothesis Testing, covering 7.1 Hypothesis Testing, 7.2 Finding Critical Values, 7.3 One-Tailed Tests, and 7.4 Two-Tailed Tests. Each one has a worked solution and a mark scheme showing where the marks go.