Probability question: Based on reports from state health departments, there were 10.33 cases of tuberculosis per 100,000 population in the United States in 1990. What is the probability of a health department, in a county of 50,000, observing 10 or more cases in 1990 if the U.S. rate held in the county? What is the probability of fewer than 3 cases in this same county if the U.S. rate held in the county?