The length of the bus journey from Leeds to London is normally distributed with a mean of 240 minutes and a standard deviation of 12 minutes.
Find the probability of a bus taking longer than 260 minutes.
Write down a null and alternative hypothesis for a two-tailed test.
They take a sample of 9 bus journeys and find a mean time of 252 minutes. Test at the 1% significance level whether there is evidence that the mean time has changed.
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.