The scientists found that the level of carbon dioxide in the air did not cause college students to yawn more frequently.What other experiment could they conduct to confirm that they should reject the hypothesis that yawning is regulated in the same way as breathing?
A)Test the effect of hemoglobin amounts on the frequency of yawning.
B)Test the effect of exercise levels on the frequency of yawning.
C)Test the effect of carbon monoxide (CO)levels on the frequency of yawning.
D)Test the effect of diet on the frequency of yawning.

Question

Quizplus · Accepted Answer

Testing the effect of exercise levels on the frequency of yawning would be a good choice because it would allow scientists to see if yawning is related to the amount of oxygen in the body or if it is related to something else entirely. This would be a valid test of the hypothesis because it involves a different variable than the carbon dioxide levels in the air. Choices A, C, and D do not relate to the hypothesis that yawning is regulated in the same way as breathing.

The Scientists Found That the Level of Carbon Dioxide in the Air