A national survey claims that the average time adults spend on exercise is 45 minutes per day. A fitness researcher suspects that members of a specific gym spend more time than this. She takes a random sample of 64 gym members and finds their mean daily exercise time is 48.5 minutes with a standard deviation of 12 minutes. Test, at the 5% level of significance, the researcher's claim. State your hypotheses clearly.
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.