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.
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.