In a study designed to determine the percentage of doctors belonging to the American Medical Association (AMA) who perform pro bono work, the AMA found from a census of its membership that 63% performed pro bono work. The AMA also found from a sample of 1000 members that the average number of pro bono hours worked by a doctor in a year was 223.

(a) What is the target population in this study?

(b) Is 63% a statistic or a parameter? Explain.

(c) Is 223 a statistic or a parameter? Explain.