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.
Practise Edexcel A Level Maths The Normal Distribution with exam-style questions for A Level Maths. 100 questions covering The Normal Distribution, Finding Probabilities for Normal Distributions, The Inverse Normal Distribution Function, The Standard Normal Distribution, Finding the mean and standard deviation, Approximating a Binomial Distribution, and Hypothesis Testing with the Normal Distribution, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.