A manufacturer of energy drinks claims that each can contains a mean caffeine content of 160 mg.
A nutritionist suspects that the caffeine content is actually lower than 160 mg.
The nutritionist tests a sample and records the following summary statistics:
n=150∑x=23745∑x2=3776363 n = 150 \quad \sum x = 23745 \quad \sum x^2 = 3776363 n=150∑x=23745∑x2=3776363Find the mean and standard deviation of the sample.
Carry out a hypothesis test to test the nutritionist's claim at the 1% significance level. State your assumptions clearly.
390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.