An environmental scientist finds that the probability of a soil sample from a specific industrial region containing high levels of lead is 0.08. Samples are collected independently.
In a random selection of 50 soil samples, determine the probability that at least 7 samples contain high levels of lead.
A construction company analyzes a large batch of 600 soil samples. The entire site undergoes a mandatory decontamination process if more than 60 samples in the batch are found to have high lead levels.
Use a suitable approximation to estimate the probability that the site undergoes the decontamination process.
67 exam-style questions on OCR (MEI) A Level Maths 2.4.13 Model with probability distributions. Each one has a worked solution and a mark scheme showing where the marks go.