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2.2.12 Variance and standard deviation

2.2.12 Variance and standard deviation

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Question 1

Eight observations have Sxx=98S_{xx}=98Sxx​=98. A ninth observation, equal to the mean of the original eight observations, is added.

a.

Explain why neither the mean nor SxxS_{xx}Sxx​ changes.

[2]
b.

Calculate the sample standard deviation of the nine observations.

[2]
Markscheme

2.2.12 Variance and standard deviation Questions

  1. A Level
  2. /Maths
  3. /2.2.12 Variance and standard deviation

8 exam-style questions on OCR (MEI) A Level Maths 2.2.12 Variance and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.

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