Posted by Brenda on .
Suppose that more than a decade ago high levels of lead in the blood put 81 percent of children at risk. A concerted effort was made to remove lead from the environment. Suppose, according to a survey, only 5 percent of children in the United States are at risk of high blood-lead levels. In a random sample of 150 children taken more than a decade ago, what is the probability that 110 or more had high blood-lead levels?