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4.1.1 Probability (A-level only)

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Question 3

The operating lifespan, LLL cycles, of Titan-X high-performance drone batteries is normally distributed with a mean of 450450450 cycles and a standard deviation of 404040 cycles.

a.

Find the probability that a randomly selected Titan-X battery lasts for more than 530530530 cycles.

[2]
b.

Batteries that exceed a lifespan of 530530530 cycles are designated as "Elite".

A battery is selected at random. Given that it is designated as Elite,

determine the probability that its lifespan exceeds 550550550 cycles.

[3]
c.

Within the Elite category, exactly 15%15\%15% of batteries have a lifespan exceeding kkk cycles.

Find the value of kkk.

[3]

4.1.1 Probability (A-level only) Questions

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