The probability that a recipient of a charity's email signs up to volunteer is 0.12. The charity rewrites the email and believes this will increase the population probability of a recipient signing up. After the change, 16 of a random sample of 80 recipients sign up.
Test the charity's belief at the 5% level of significance. State your hypotheses clearly.
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.