The weight of beans in a tin produced by company A normally distributed with a mean of 415 g and a standard deviation of 3.4 g.
Find the probability that a randomly selected tin of beans has a weight of less than 409 g.
Company A suspects that the mean weight of tins from a machine is lower than it should be.
Write down the company's null and alternative hypothesis.
A sample of 20 tins is taken and the mean weight is found to be 413 g.
Carry out a test at the 1% significance level to see if there is evidence that the machine is producing tins with a mean of less than 415 g.
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.