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3.5 Finding the mean and standard deviation

3.5 Finding the mean and standard deviation

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Question 35

The volumes of liquid in a batch of artisan coffee pods are modelled by a normal distribution with mean μ\muμ ml and standard deviation σ\sigmaσ ml. Data from the quality control lab indicates that 8% of the pods contain more than 42 ml of liquid, while 4% of the pods contain less than 35 ml.

a.

Sketch a diagram to represent this information, illustrating the distribution of the volumes.

[2]
b.

Show that μ=42−1.4051σ\mu = 42 - 1.4051\sigmaμ=42−1.4051σ.

[3]
c.

Determine a second linear equation involving μ\muμ and σ\sigmaσ, and hence calculate the value of μ\muμ and the value of σ\sigmaσ to 2 decimal places.

[5]
d.

Calculate the probability that a randomly selected pod from this batch contains more than 37 ml of liquid.

[3]
Markscheme

3.5 Finding the mean and standard deviation Questions

  1. A Level
  2. /Maths
  3. /3.5 Finding the mean and standard deviation

48 exam-style questions on Edexcel A Level Maths 3.5 Finding the mean and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.

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