A food processing plant packs cereal into boxes with a target mean weight of 500g. A quality control inspector believes the machine is underfilling the boxes. A random sample of 100 boxes is weighed, giving the following statistics:
n=100∑x=49910∑x2=24912581 n = 100 \quad \sum x = 49910 \quad \sum x^2 = 24912581 n=100∑x=49910∑x2=24912581Find the mean and standard deviation of the sample.
Carry out a hypothesis test to test the inspector's belief at the 1% significance level. State your assumptions 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.