A botanical research study finds that 45% of seeds from a specific hybrid perennial germinate within the first 10 days of being sown. The seeds are packaged in sachets of 20 for commercial sale. A sachet is selected at random.
Determine the probability that the sachet contains exactly 9 seeds that germinate within 10 days.
Determine the probability that there are at least 13 seeds in the sachet that germinate within 10 days.
Using a suitable approximation, find the probability that in a bulk tray of 200 seeds, between 80 and 105 seeds (inclusive) germinate within 10 days.
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.