Garret studies number of hours sleep per night among students who have a grade point average of 3.0–4.0 versus students who have a grade point average of 2.0–3.0. His theory is that students who get more sleep will have a higher grade point average than students who get less sleep because they are more rested and, therefore, better able to concentrate.

In his samples, the mean number of hours of sleep students with a grade point average of 3.0–4.0 received each night was 6.8. The mean number of hours of sleep students with a grade point average of 2.0–3.0 received each night was 6.4.

Assuming there are no outliers or skew, do the results support Garret's theory?

Select from the drop-down menus to correctly complete the statements.

Since the samples were large and randomly chosen, we can use the samples to understand the populations.

Because the sample mean for students with a grade point average of 3.0–4.0 is
1. a. less than b. greater than c. about the same as
the sample mean for students with a grade point average of 2.0–3.0, the results
2. a. tend to b. do not tend to
support Garret's theory.