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2 Statistics

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Question 71

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 Statistics Questions

  1. A Level
  2. /Maths
  3. /2 Statistics

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