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.
