A lightbulb manufacturer claims that only 2%2\%2% of its LED bulbs are defective. To investigate this claim, a quality control manager selects a random sample of 150150150 bulbs and finds that 888 are defective.
Use a suitable approximation to test, at the 5%5\%5% level of significance, whether the manufacturer is understating the proportion of defective bulbs. State your hypotheses clearly.
616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.