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2 Statistics

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Question 77

Ten observations have ∑x=120\sum x=120∑x=120 and ∑x2=2000\sum x^2=2000∑x2=2000. The value 30 is then found to be an erroneous entry and is removed.

a.

Calculate the original mean and standard deviation.

[3]
b.

Calculate the mean and standard deviation after the entry is removed.

[3]
c.

Describe the effect of removing the entry.

[1]
Markscheme

2 Statistics Questions

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

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