Marine biologists monitoring a coral reef find that the probability of a specific coral colony showing signs of thermal stress is 0.40. They survey a reef section containing 200 individual colonies.
Using a suitable approximation, estimate the probability that more than 75 colonies in the section show signs of thermal stress.
A researcher examines 3 separate sections of the reef, each containing 200 colonies.
Estimate the probability that at least 76 colonies show signs of thermal stress in each of the 3 sections.
616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.