A company produces pens. The probability that any pen is defective is 0.1.
A sample of 20 pens is taken. Find the probability that 2 or more pens are defective.
An employee claims that the probability that a pen is defective is more than 0.1. They take a sample of 25 pens and 6 are defective. Stating your hypothesis clearly, test the employee's claim at the 5% significance level.
153 exam-style questions on Edexcel A Level Maths Hypothesis Testing, covering 7.1 Hypothesis Testing, 7.2 Finding Critical Values, 7.3 One-Tailed Tests, and 7.4 Two-Tailed Tests. Each one has a worked solution and a mark scheme showing where the marks go.