A marine biologist claims that 12% of the coral reef sections in a protected lagoon exhibit signs of thermal bleaching. A researcher, suspecting the biologist is understating the severity of the bleaching, examines a random sample of 450 sections and identifies 62 that are bleached.
Using a suitable approximation, test at the 5% significance level whether there is evidence to support the researcher's suspicion. State your hypotheses clearly.
67 exam-style questions on OCR A Level Maths 2.4.4 Mean and variance of the binomial (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.