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.
616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.