The weights of crates that are delivered to a warehouse are normally distributed with a mean of 25 kg and a standard deviation of 4.5 kg.
Find the probability that a randomly selected crate weighs more than 33 kg.
The lightest 20% of crates are handled by a specialized automated conveyor system.
Find the weight, in kg, of the heaviest of these crates that the conveyor system will handle.
One of the crates not handled by the conveyor system is selected at random.
Find the probability that it weighs less than 28 kg.
A shipment of 5 crates is delivered to the warehouse. The weights of the crates are independent.
Find the probability that exactly 3 of them will be handled by the conveyor system.
390 exam-style questions on OCR (MEI) A Level Maths 2.4 Probability Distributions, covering 2.4.1 Recognise binomial situations, 2.4.2 Probability of success p, 2.4.3 Calculate binomial probabilities, 2.4.4 Mean of the binomial distribution, 2.4.5 Expected frequencies for binomial, 2.4.6 Probability functions and discrete random variables, 2.4.7 Numerical probabilities for a simple distribution, 2.4.8 Normal distribution as a model (A-level only), 2.4.9 Shape of the Normal curve (A-level only), 2.4.10 Linear transformation and standardising (A-level only), 2.4.11 Symmetry and inflection of Normal curve (A-level only), 2.4.12 Calculate probabilities from a Normal distribution (A-level only), 2.4.13 Model with probability distributions, and 2.4 Probability Distributions. Each one has a worked solution and a mark scheme showing where the marks go.