For each of the following exercises, identify: a. the population, b. the sample, c. the variable being tested. If there is no variable being tested, indicate that. (8) a. A soccer instructor wants to determine how many jerseys to buy, so they decide to calculate the average number of players in the roster, based on the last five years of data. b. A zoologist suspects that a local fertilizer is negatively affecting the health of a species of salmon. They decide to take a boat out to sea, where they tag the first 100 salmon they catch, so they can monitor their living habits. c. A game designer suspects that a certain speed of background music makes players more willing to focus. In order to find participants, they use the company database which contains all employees. They decide to ask 10 random people to play with the background music, and 10 random people to play without. The designer then records each individual's opinion. d. A swimming instructor is interested in the mean age of students when they attend their first swimming class, so they can plan for future classes. They examine the last 200 students in the database.