A pharmaceutical lab fills vials with a reagent. The volume of reagent in a vial, VVV ml, is modeled by a normal distribution with mean 125.2125.2125.2 ml and standard deviation 0.850.850.85 ml.
Determine the probability that the volumes of reagent in two randomly chosen vials differ by more than 2.02.02.0 ml.
Vials are transported in batches of 15 using a specialized storage rack. The volume of the storage rack itself, RRR ml, is modeled by a normal distribution with mean 320.0320.0320.0 ml and standard deviation 2.52.52.5 ml.
Calculate the probability that the total volume of a randomly selected storage rack fully loaded with 15 vials exceeds 220522052205 ml.
390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.