The proportion of visitors to a webpage who click on a link is 0.15. Angela believes that increasing the font size of the link will increase this proportion.
After the font size is increased, a random sample of 90 visitors is taken, and 20 of them click on the link.
Stating your hypotheses clearly, test Angela's belief at the 5% significance level.
32 exam-style questions on WJEC A Level Maths 2.5.1 Statistical hypothesis testing. Each one has a worked solution and a mark scheme showing where the marks go.