A student reports that, of a simple random sample of 25 college undergraduate students, 18% were working at least two jobs. We know that the student has made a mistake (or maybe really did not conduct the survey). Why?
A) There are 25 students in the sample, so percentages should be multiples of 0.04%.
B) There are 25 students in the sample, so percentages should be multiples of 4%.
C) 18% of 25 students is 4.5 students, and you cannot sample a half of a student.
D) Both A and C are correct.
E) Both B and C are correct.

Question

Quizplus · Accepted Answer

Given a sample of 25 students, the smallest change in count (1 student) corresponds to a 4% change in percentage (since 1/25 = 0.04 or 4%). Also, 18% of 25 is 4.5, which is not possible since you cannot have half a student. Therefore, both B and C are correct reasons.

A Student Reports That, of a Simple Random Sample of 25