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

Question

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?
The number of sides on a cube does not match the number of grade levels.
The number of sides on a cube is not a factor of the total number of students.
The number of outcomes representing each grade level does not change after the first student is chosen.
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

The best statement that describes the flaw in Jeremy’s model is:

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

In his simulation, rolling a cube with 6 sides leads to different probabilities for selecting grade 7 and grade 8 students. Specifically, two outcomes (1 or 2) represent grade 7 students while four outcomes (3, 4, 5, or 6) represent grade 8 students. This means that the simulation does not accurately reflect the actual proportions of grade 7 and grade 8 students in the student council (17 grade 7 out of a total of 51 students). Therefore, the outcomes in Jeremy's model do not reflect the true probabilities of selection based on the given proportions of students from each grade.