A logistics company finds that 35% of their long-distance delivery drones require a battery recalibration after each flight.
State a distribution that is suitable to model the number of drones requiring recalibration in a random selection of 20 drones.
State two conditions for the distribution in part (a) to be a valid model.
Find the probability that: exactly 8 drones in a selection of 20 require recalibration,
Find the probability that: fewer than 12 drones in a selection of 40 require recalibration.
A maintenance supervisor notes that the technical team will be overwhelmed if more than 100 drones in a daily batch of 250 require recalibration.
Using a suitable approximation, find the probability that the technical team will be overwhelmed in a particular batch of 250 drones.
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.