The weight of beans in a tin produced by company A is normally distributed with a mean of 420 g and a standard deviation of 4 g.
A sample of 16 tins is taken and the mean weight is found to be 417 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 420 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.