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4.2 Statistical distributions (A-level only)

4.2 Statistical distributions (A-level only)

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Question 71

The operational lifespans of deep-sea sensor modules, TTT hours, are normally distributed such that T∼N(μ,402)T \sim \text{N}(\mu, 40^2)T∼N(μ,402).

a.

Given that 15%15\%15% of the modules have a lifespan exceeding 120012001200 hours, calculate the value of μ\muμ correct to the nearest 0.10.10.1 h.

[3]
b.

An oceanographer selects 121212 modules at random.

Determine the probability that fewer than 222 of these modules have a lifespan exceeding 120012001200 hours.

[3]
c.

A research station deploys 250250250 modules.

By employing a suitable approximation, find the probability that more than 454545 of these modules have a lifespan exceeding 120012001200 hours.

[5]
Markscheme

4.2 Statistical distributions (A-level only) Questions

  1. A Level
  2. /Maths
  3. /4.2 Statistical distributions (A-level only)

328 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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