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2 Unit AS 2: Applied Mathematics

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Question 40

Group A contains 20 observations with mean 10 and variance 4. Group B contains 30 observations with mean 14 and variance 9.

a.

Show that the mean of all 50 observations is 12.4.

[1]
b.

Calculate the variance of all 50 observations.

[3]
c.

Explain why the combined variance is greater than either group variance.

[1]
Markscheme

2 Unit AS 2: Applied Mathematics Questions

  1. A Level
  2. /Maths
  3. /2 Unit AS 2: Applied Mathematics

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