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.
