The random variable X X\,X has the distribution X∼B(12,p)X \sim B(12, p)X∼B(12,p), and P(X=0)=0.0687P(X = 0) = 0.0687P(X=0)=0.0687 to 3 significant figures.
Show that p=0.2p = 0.2p=0.2.
Hence find P(X≥3)P(X \ge 3)P(X≥3).
Find P(X=1)P(X=1)P(X=1).
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.