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.
316 exam-style questions on OCR A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 The language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, 2.5.3 Inference and significance level, 2.5.4 Sample mean as a random variable (A-level only), 2.5.5 Hypothesis test for the mean of a normal distribution (A-level only), 2.5.6 Pearson's product-moment correlation coefficient, and 2.5.7 Hypothesis test using Pearson's coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.