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).
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.
An oceanographer selects 121212 modules at random.
Determine the probability that fewer than 222 of these modules have a lifespan exceeding 120012001200 hours.
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.
Practise Edexcel A Level Maths Approximating a Binomial Distribution with exam-style questions for A Level Maths. 68 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.