The burst altitude of SkyBound meteorological balloons, HHH metres, is normally distributed with mean 32,000 metres and standard deviation 1,400 metres.
(i) Find P(H≠32000)P(H \neq 32000)P(H=32000).
(ii) Find P(30000<H<35000)P(30000 < H < 35000)P(30000<H<35000).
Determine the altitude exceeded by 70% of SkyBound balloons.
A competing brand, AeroVantage, has a burst altitude YYY metres modelled by a normal distribution with mean 28,000 metres and standard deviation σ\sigmaσ. Given that 18% of randomly selected AeroVantage balloons burst below 26,000 metres, find the value of σ\sigmaσ, correct to three significant figures.
616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.