18 (3.24) (a) give an example of a way to choose a sample of students that is poor practice because it depends on voluntary response. ask your friends to participate in the study. hang a sign that asks people to call a number to participate in a study about parking on campus. all the answers are correct.

All the answers are correct.

In order for a study to produce results that are significant for the population, the sample needs to be representative. One of the most important factors in making that sample representative is electing subjects in a random manner.

If the subjects are chosen from a group of friends or as volunteers, it is likely that sample will share common characteristics in higher numbers than the ones found in the population. Therefore, the final results could be biased.

answer; the above statement is (false);