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2 Unit 2: Applied Mathematics A

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Question 94

Twenty values have mean 12, and for these values ∑x2=2960\sum x^2 = 2960∑x2=2960.

One further value, ccc, is added. The mean of the resulting 21 values is 12.5.

a.

Find the value of ccc.

[2]
b.

Find the standard deviation of the 21 values.

[3]
c.

The standard deviation of the original 20 values is 2. Explain why the standard deviation of the 21 values is larger.

[1]
Markscheme

2 Unit 2: Applied Mathematics A Questions

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

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