Question

In the survey of a random sample of students at a university, two questions were, “How many hours per week do you usually study?” and “Have you smoked marijuana in the past six months?” An analysis of the results produced the following SPSS output:

  

A research question of interest is whether students who have smoked marijuana (group Y) in the past 6 months differ in study hours on average per week than those who have not (group N).

Using the information given in the output, what conclusion can be made about the confidence interval?

	A.	We can be 95% confident that the average study time for the group that said Yes to having smoked marijuana in the past six months is between -5.55 and -0.69 hours less per week than the group that did not smoke marijuana.
	B.	We can be 95% confident that the average study time for the group that said Yes to having smoked marijuana in the past six months is between 0.69 and 5.55 hours less per week than the group that did not smoke marijuana.
	C.	We can be 95% confident that the average study time for the group that said No to having smoked marijuana in the past six months is between 0.69 and 5.55 hours less per week than the group that did smoke marijuana.
	D.	We can be 95% confident that the average study time for the group that said Yes to having smoked marijuana in the past six months is between 0.69 and 5.55 hours more per week than the group that did not smoke marijuana.

Answer 1

The correct interpretation is:

We can be 95% confident that the average study time for the group that said Yes to having smoked marijuana in the past six months is between 0.69 and 5.55 hours less per week than the group that did not smoke marijuana.

Option B is correct.