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2.5.3 Hypothesis test for a Normal mean (A-level only)

2.5.3 Hypothesis test for a Normal mean (A-level only)

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Question 9

The lifetime of a certain type of battery is normally distributed with a mean of 48 hours and a standard deviation of 4.5 hours.

a.

Find the probability of a battery lasting longer than 55 hours.

[2]
b.

Write down a null and alternative hypothesis for a two-tailed test.

[1]
c.

A technician takes a sample of 20 batteries and finds a mean lifetime of 51 hours. Test at the 2% significance level whether there is evidence that the mean lifetime has changed.

[3]
Markscheme

2.5.3 Hypothesis test for a Normal mean (A-level only) Questions

  1. A Level
  2. /Maths
  3. /2.5.3 Hypothesis test for a Normal mean (A-level only)

130 exam-style questions on AQA A Level Maths 2.5.3 Hypothesis test for a Normal mean (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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