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4.5.1 Statistical distributions (A-level only)

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Question 69

A scientific research team uses two types of atmospheric sensors. The operational duration of each sensor is normally distributed. A Type-A sensor has a mean duration of 180 hours and a standard deviation of 8 hours. A Type-B sensor has a mean duration of 42 hours and a standard deviation of 3 hours.

a.

Determine the probability that the duration of a single Type-A sensor exceeds the combined duration of four randomly selected Type-B sensors.

[5]
b.

Find the probability that the duration of one Type-A sensor is less than four times the duration of a single, randomly selected Type-B sensor.

[5]
Markscheme

4.5.1 Statistical distributions (A-level only) Questions

  1. A Level
  2. /Maths
  3. /4.5.1 Statistical distributions (A-level only)

225 exam-style questions on CCEA A Level Maths 4.5.1 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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