Question

6.20. A convenience store owner wants to know how long his customers spend browsing the store before making a purchase. It is found that time spent is normally distributed with an average of μ = 5 minutes and a standard deviation of σ = 2.2 minutes. Using a random sample of 14 customers, what is the probability that a customer, on average, will spend less than 4 minutes browsing the store?

6.21. It is estimated that 66% of new businesses fail during the first ten years. What is the probability that in a sample of 30 startups, more than half will fail in the first ten years?

Answer 1