On-site treatment of hazardous waste. The Resource Conservation and Recovery Act mandates the tracking and disposal of hazardous waste produced at U.S. facilities.

Professional Geographer (Feb. 2000) reported the hazardous-

waste generation and disposal characteristics of 209 facilities. Only 8 of these facilities treated hazardous waste on-site.

a. In a random sample of 10 of the 209 facilities, what is the expected number in the sample that treat hazardous waste on-site? Interpret this result.

b. Find the probability that 4 of the 10 selected facilities treat hazardous waste on-site.