The mass of sugar in a standard packet is modelled by a normal distribution with a mean of 1000 g and a standard deviation of 20 g.
Using this model, find the probability that a randomly selected packet contains more than 1035 g of sugar.
A quality control inspector suspects that the filling machine is overfilling and the mean mass is greater than 1000 g. A random sample of 25 packets is taken and the mean mass is found to be 1010 g. Test the inspector's suspicion at the 5% level of significance. State your hypotheses clearly.
209 exam-style questions on CCEA A Level Maths 4.6 Statistical hypothesis testing (A-level only), covering 4.6.1 Statistical hypothesis testing (A-level only), 4.6.2 Statistical hypothesis testing (A-level only), 4.6.3 Statistical hypothesis testing (A-level only), 4.6.4 Statistical hypothesis testing (A-level only), and 4.6.5 Statistical hypothesis testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.