Indicate whether each of the following constitutes data collected from a population or a sample. a. A

Question:

Indicate whether each of the following constitutes data collected from a population or a sample.
a. A group of 25 patients selected to test a new drug
b. Total items produced on a machine for each year from 1995 to 2012
c. Yearly expenditures on clothes for 50 persons
d. Number of houses sold by each of the 10 employees of a real estate agency during 2012