Question

The table shows the number of grade 7 and grade 8 students on the student council at Jeremy’s school.

Grade Levels of Student Council Members

Number of Students
Grade 7
17
Grade 8
34

Every day, two student council members are randomly chosen to read the morning announcements. Students cannot be chosen more than once to read the announcements. Jeremy designed a simulation for the selection of the students and gathered data to predict the probability that a seventh grade student will be chosen. In Jeremy’s simulation, he rolls two number cubes in each of 40 trials. In each trial, a cube landing on 1 or 2 represents a student in grade 7 being selected, and a cube landing on 3, 4, 5, or 6 represents a student in grade 8.

Which statement best describes the flaw in Jeremy’s model?
A. The number of sides on a cube does not match the number of grade levels.
B. The number of sides on a cube is not a factor of the total number of students.
C. The number of outcomes representing each grade level does not change after the first student is chosen.
D. The number of outcomes representing a student in grade 7 is not the same as the number representing a student in grade 8.

Answer 1

D. The number of outcomes representing a student in grade 7 is not the same as the number representing a student in grade 8.

In Jeremy's model, the number of outcomes for a grade 7 student (1 or 2) and a grade 8 student (3, 4, 5, or 6) are not equal. This means that the probabilities of a grade 7 student being chosen and a grade 8 student being chosen are not equal, which makes his simulation flawed.