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.
316 exam-style questions on OCR A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 The language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, 2.5.3 Inference and significance level, 2.5.4 Sample mean as a random variable (A-level only), 2.5.5 Hypothesis test for the mean of a normal distribution (A-level only), 2.5.6 Pearson's product-moment correlation coefficient, and 2.5.7 Hypothesis test using Pearson's coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.