Mathematics 9709 · AS & A Level · Hypothesis testing
Hypothesis testing — practice question
An inspector thinks that 18% of the cups produced at a particular factory are defective. The factory owner says that the actual proportion is below 18%. A random sample of 40 cups is checked by the inspector, and 3 of those cups are found to be defective.
(a)[6]
State a required assumption, then use a binomial distribution to test the factory owner’s claim at the 5% significance level.
(b)[1]
Explain why it would not be suitable to use the Poisson approximation to the binomial distribution when carrying out the test in part (a).
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Defects in cups are independent or the probability of a defect is constant for every cup” …