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2.4 Statistical Distributions

2.4 Statistical Distributions

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Question 144

The cooling system for a quantum processor is monitored during a stability test. The operating temperature, TTT Kelvin, is modelled by a normal distribution with a mean of 84.284.284.2 K.

a.

Sketch the distribution of TTT. Label the mean on your sketch.

[1]
b.

The target operating limit for the system is 82.582.582.5 K. The standard deviation of the system's temperature is 1.41.41.4 K.

Find the percentage of time that the system operates below the target limit of 82.582.582.5 K.

[2]
c.

The coldest 1.5%1.5\%1.5% of temperature readings trigger an automatic safety shutdown.

Show that the maximum temperature to trigger a safety shutdown, correct to 3 significant figures, is 81.281.281.2 K. Show your working clearly.

[3]
d.

Maintenance alerts are issued if a temperature reading ttt falls in a range such that:

P(t<T<82.5)=0.075 P(t < T < 82.5) = 0.075 P(t<T<82.5)=0.075

Find the value of ttt, giving your answer to 1 decimal place. Show your working clearly.

[4]
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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