Question

suppose you are interested in whether or not the students at your high school would favor a grading system in which students may receive final grades of a+, a, a-, b+, b, b-, c+, c, c- and so on. describe how you might obtain a random sample of 100 students from the entire student population. choose the correct answer below. a. determine the ten streets on which the most students at the school live. then, select ten students from each street. if fewer than ten students live on a street, fill in the spot with a randomly selected student. b. assign each student at the school a number, write each number on a card, and place all of the cards in a box. then, randomly select 100 cards. c. sort the students by their overall average grades. then, select the 50 students with the best grades and the 50 students with the worst grades. d. post an advertisement requesting the assistance of 100 students. among the first 100 students to arrive, select them in a random order.

Explanation:

Step1: Analyze option A

This method is not random sampling. It focuses on students from certain streets, which may introduce bias as it doesn't give equal chance to all students in the population.

Step2: Analyze option B

Assigning each student a number, writing on cards and randomly selecting 100 cards is a simple random sampling method. Each student has an equal chance of being selected.

Step3: Analyze option C

Sorting by grades and selecting based on grade - performance (best and worst) is a form of stratified sampling but not a simple random sample. It pre - defines groups based on grades and may not represent the entire student population's opinion on the grading system fairly.

Step4: Analyze option D

Selecting the first 100 students who respond to an advertisement is a convenience sample. It is likely to be biased as only students who see the ad and are interested in responding (which may be related to their opinion on the grading system) are included.

Answer:

B. Assign each student at the school a number, write each number on a card, and place all of the cards in a box. Then, randomly select 100 cards.