The average age in a sample of 90 students at City College is 20.From this sample, it can be concluded that the average age of all the students at City College _____.
A) must be more than 20, since the population is always larger than the sample
B) must be less than 20, since the sample is only a part of the population
C) could not be 20
D) could be larger, smaller, or equal to 20

Question

Quizplus · Accepted Answer

Since the average age of the sample is 20, it is possible that the average age of the entire population is also 20. However, it is also possible that the average age of the entire population is either larger or smaller than 20. Therefore, the best choice is D, which states that the average age could be larger, smaller, or equal to 20.

The Average Age in a Sample of 90 Students at City