A bakery produces loaves of bread whose weights, WWW grams, follow a normal distribution with mean 800 g800\text{ g}800 g and standard deviation 25 g25\text{ g}25 g.
Estimate the proportion of loaves that weigh more than 840 g840\text{ g}840 g.
The bakery classifies loaves into three categories: Small, Standard, and Large, such that there is an equal proportion of loaves (exactly 13\frac{1}{3}31) in each category.
Find the weight limits that define the 'Standard' category.
A loaf is selected at random from the 'Large' category.
Find the probability that this loaf weighs less than 830 g830\text{ g}830 g.
A customer selects a random sample of 3 loaves from the bakery's total production.
Find the probability that there is exactly one loaf from each of the three categories.
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.