In a manufacturing process for specialized solar cells, the probability that a cell is classified as 'High Efficiency' grade is 0.35.
Find the probability that
in a random sample of 8 cells, exactly 2 are classified as High Efficiency.
in a random sample of 20 cells, the number of High Efficiency cells is more than 10.
A quality control manager inspects a large delivery of 400 cells.
Using a suitable approximation, determine the probability that the delivery contains fewer than 130 High Efficiency cells.
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.