students and that the examination period is 90 minutes in length. How many students do you expect will be unable to complete the exam in the allotted time?

Although studies continue to show smoking leads to significant health problems, 20% of adults in the United States smoke. Consider a group of 250 adults. Use normal approximation to binomial distribution to compute the following probabilities.

a)What is the expected number of adults who smoke?

b)What is the probability that fewer than 40 smoke?

c)What is the probability that from 55 to 60 smoke?

d) What is the probability that 70 or more smoke.

Thirty diabetics have volunteered for a medical study. Ten of the diabetics have high blood pressure. Five are selected for a preliminary screening for the study. What is the probability that none of the five selected have high blood pressure if the selection is done randomly?