What you’ll learn3 learning objectivesChoose one objective for a focused lesson, or study the complete topic.5.4.1Discrete random variables• draw up a probability distribution table relating to a given situation involving a discrete random variable X, and calculate E(X) and Var(X)Syllabus objective5.4.2Geometric distribution• use formulae for probabilities for the binomial and geometric distributions, and recognise practical situations where these distributions are suitable models Including the notations B(n, p) and Geo(p). Geo(p) denotes the distribution in which pr = p(1 - p)r - 1 for r = 1, 2, 3, ….Syllabus objective5.4.3Expectation and variance• use formulae for the expectation and variance of the binomial distribution and for the expectation of the geometric distribution. Proofs of formulae are not required.Syllabus objective