The mass of a bag of flour produced at a factory is normally distributed with a mean of 1500 g and a standard deviation of 20 g.
Find the probability of a bag weighing more than 1545 g.
The quality control manager suspects that the mean mass of the flour bags has changed.
Write down a null and alternative hypothesis for a two-tailed test.
They take a random sample of 25 bags and find a mean mass of 1512 g.
Test at the 5% significance level whether there is evidence that the mean mass has changed.
132 exam-style questions on Edexcel A Level Maths 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.