Assignment:
In conducting his study of reactions to unemployment, Peter tries to select every 10th unemployed person in his country for a telephone interview. Peter had trouble identifying the entire population (no central lists were kept) and could not contact all the potential participants he could identify, because some of them did not have telephones. Which of the following is true about his study?
a. He used systematic random sampling
b. He used simple random sampling
c. His sample is representative of the populations
d. His sample is not a truly random sample