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2.2.12 Variance and standard deviation

2.2.12 Variance and standard deviation

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Question 4

Distances travelled by 100 people are grouped. Using class midpoints gives ∑fx=2651\sum fx=2651∑fx=2651 and ∑fx2=80434.25\sum fx^2=80434.25∑fx2=80434.25. Linear interpolation gives a median of 26.1 miles.

a.

Estimate the mean distance.

[2]
b.

Estimate the sample standard deviation.

[3]
c.

Compare the mean and median and give a cautious comment about skew.

[1]
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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