Answer:
Population here, refers to the total set of observations that can be made.
A population denotes a larger group consisting of same type elements.
1. Using a yearbook to determine the most popular names for girls in the United States. This is not fair as a yearbook of a single school or two to three schools cannot determine the popular names in the whole US.(it is not mentioned how many yearbooks are to be selected, so I will mark this not fair.)
2. Asking the people exiting a vitamin store how often they exercise to determine the amount of time the average American exercises. This is not fair as, often how many people visit such stores daily. So, to determine the amount of time the average American exercises cannot be derived by using this method.
3. Calling every registered member of the national Republican Party to determine the voter turnout for a city’s mayoral race. This is not fair as only a single party has been selected here.
4. Sending a mandatory and confidential e-mail survey to every tenth employee of a company to determine overall job satisfaction. This is fair as every 10th person is randomly selected. So, say if the company has 1000 employees, so every 10th will become a total of 100 employees. This represent the whole population.
5. Taking a poll in the main hallway between classes to determine the number of students who would be interested in a school trip to New York City. This is fair as you will randomly select any number of students passing through the hallway.
