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.
328 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.