The total duration of oxygen supply, SSS minutes, for a specific model of deep-sea diving tank is modelled by a normal distribution with a mean of 210 minutes and a standard deviation of 25 minutes.
Determine the probability that a randomly selected tank will last for more than 260 minutes.
Find the value of kkk such that P(S<k)=0.12P(S < k) = 0.12P(S<k)=0.12.
A diver has already been submerged for 260 minutes using one of these tanks. To safely reach the surface, they require a further 15 minutes of oxygen.
Calculate the probability that the tank will not run out of oxygen before the diver reaches the surface.
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.