Question

Cynthia concludes that 8th graders are more likely than 9th graders to spend at most four hours per week studying because more 8th graders than 9th graders responded that they study this long.

Explain whether Cynthia is correct. Include all necessary work to support your answer.

Answer 1

To determine whether Cynthia's conclusion is correct, we need to look at the data she is referring to. Specifically, we need to compare the percentage of 8th graders who reported studying at most four hours per week to the percentage of 9th graders who reported the same.

Let's say that out of 100 8th graders surveyed, 60 reported studying at most four hours per week. That means the percentage of 8th graders who study at most four hours per week is:

60/100 = 0.6 or 60%

Now let's say that out of 100 9th graders surveyed, 40 reported studying at most four hours per week. That means the percentage of 9th graders who study at most four hours per week is:

40/100 = 0.4 or 40%

So Cynthia's conclusion is correct. More 8th graders than 9th graders reported studying at most four hours per week, and therefore 8th graders are more likely than 9th graders to spend at most four hours per week studying.