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The Normal Distribution

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Question 124

A geologist is studying the depth, DDD metres, of carbon sequestration in a specific geological formation. The depth is modelled by a normal distribution with mean μ=1250\mu = 1250μ=1250 m and standard deviation σ=80\sigma = 80σ=80 m.

a.

Find an estimate for the proportion of sequestration sites with a depth of less than 110011001100 m.

[2]
b.

The research project involves two stages. Every site in the survey is measured in the first stage, and the deepest 12%12\%12% of sites are categorised as 'High Priority' for a more detailed second stage of testing.

Find an estimate for the minimum depth a site must have in the first stage to be categorised as High Priority. Give your answer to 4 significant figures.

[3]
c.

Determine the median depth of the High Priority sites based on the first stage measurements.

[3]
d.

The measurement in the second stage is independent of the first and follows the same normal distribution. A site receives 'Gold Status' if it is categorised as High Priority and its second stage measurement exceeds 140014001400 m.

A site is selected at random from the survey.

Find the probability that this site receives Gold Status.

[3]

The Normal Distribution Questions

  1. A Level
  2. /Maths
  3. /The Normal Distribution

Practise Edexcel A Level Maths The Normal Distribution with exam-style questions for A Level Maths. 439 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.

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