An agricultural scientist is measuring the heights of a specific variety of wheat plants, H H\,H cm, such that H∼N(μ,σ2)H \sim \operatorname{N}(\mu, \sigma^2)H∼N(μ,σ2).
A random sample of these plants is taken, and a 98% confidence interval for μ \mu\,μ is calculated as (78.14,82.26)(78.14, 82.26)(78.14,82.26).
Find, to 2 decimal places, the standard error of the mean.
Hence, or otherwise, calculate a 95% confidence interval for μ \mu\,μ based on the same sample of wheat plants.
Using five different random samples, five 95% confidence intervals for μ \mu\,μ are to be constructed.
Calculate the probability that at least 4 of these intervals will contain μ\muμ.
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.