A telecommunications engineer monitors the reliability of a satellite link. Under specific atmospheric conditions, the probability of a data packet being lost during transmission is 0.15.
State two assumptions required to model the number of packets lost in a sequence of n n\,n transmissions using a binomial distribution.
Using this model, find the probability that exactly 4 packets are lost in a random sequence of 18 transmissions.
Calculate the mean and the variance of the number of packets lost in a sequence of 160 transmissions.
A link is classified as 'unstable' if more than 30 packets are lost in a sequence of 160 transmissions.
Using a suitable approximation, find the probability that the link will be classified as 'unstable'.
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.