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 AQA A Level Maths 2.4 N: Statistical distributions, covering 2.4.1 Discrete distributions and the binomial, 2.4.2 The Normal distribution (A-level only), and 2.4.3 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.