The shelf life of a specific type of fresh bread is normally distributed.
14% of the loaves spoil in fewer than 3 days. 18% of the loaves stay fresh for longer than 7 days.
Find the mean and standard deviation of the shelf life of the bread.
390 exam-style questions on AQA A Level Maths 2.4 N: Statistical distributions, covering 2.4.1 Discrete distributions and the binomial, 2.4.2 The Normal distribution (A-level only), and 2.4.3 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.