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The Normal Distribution

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Question 18

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=3776363
a.

Find the mean and standard deviation of the sample.

[3]
b.

Carry out a hypothesis test to test the nutritionist's claim at the 1% significance level. State your assumptions clearly.

[5]
Markscheme

The Normal Distribution Questions

  1. A Level
  2. /Maths
  3. /The Normal Distribution

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.

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