Answer
A. Inferential
B. Inferential
C. Descriptive
Work Step by Step
For (a), the problem states that the population is unmeasured but that they want to reach a conclusion about that population. Thus, inferential techniques would be used because the sample would be measured and then inferences would be drawn from the sample about the population in question. For (b), inferential techniques would be used because the process of sampling is random and can depend on the luck of the draw--inferential statistics takes this into account. Lastly, (c) describes the use of descriptive statistics. As its name portrays, descriptive statistics describes data with ways such as central measures of tendency, graphs, etc.
