Difficulty: Easy/Medium
A company knows that the probability that any pen it produces is defective is 0.08. An employee claims that the probability is now greater than 0.08.
The employee takes a random sample of 25 pens, and 5 of them are defective.
Stating your hypotheses clearly, test the employee's claim 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.