Answer: C) He should also take a sample from each of the other history classes in all of the other grades in the middle school.
Step-by-step explanation:
In order for his sample to be representative of all middle school students Leo: C) Should also take a sample from each of the other history classes in all of the other grades in the middle school.
Sample can be defined as the data that is randomly collected by a researcher so as to reach or draw a conclusion.
Since only one grade is being surveyed which is Mr. Barnes’s eighth-grade history classes, he should as well carryout the survey on Ms. Lopez and Mrs. Frank history class.
Inconclusion he should also take a sample from each of the other history classes in all of the other grades in the middle school.
Not only students in the 8th grade are in the middle school, there are other students in other grades who are in the middle school and are enrolled in history classes. Leo's sample is only from one grade of the middle school. In fact, including Ms. Lopez's and Mrs. Frank's classes in the selection of sample is not sufficient. Leo has to take a sample from the remaining grades to avoid making a wrong conclusion as a result of bias in the choice of data.
