The storage life of a specialized organic catalyst, CCC days, is modeled by a normal distribution with a mean of 45 days and a standard deviation of 8 days.
Calculate the probability that a randomly selected batch of this catalyst lasts longer than 60.0 days.
A 'warning threshold' is set at ddd days, such that the probability of a catalyst failing before this threshold is 0.08. Determine the value of ddd.
A laboratory process requires the catalyst to remain effective for a further 5 days. Given that a specific batch of catalyst has already been stored for 60 days and is still effective, find the probability that it will last until the process is finished.
79 exam-style questions on OCR (MEI) A Level Maths 2.4.8 Normal distribution as a model (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.