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2.4 Statistical Distributions

2.4 Statistical Distributions

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Question 43

The time, T T\,T minutes, taken for a student to complete a logic puzzle follows a normal distribution. Data shows that 25% of students complete the puzzle in less than 25 minutes, while 15% take more than 45 minutes.

Find the mean and standard deviation of the time taken to complete the puzzle.

[6]
Markscheme

2.4 Statistical Distributions Questions

  1. A Level
  2. /Maths
  3. /2.4 Statistical Distributions

390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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