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.
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.