In a correlation analysis both variables are random; in a regression analysis one is fixed.

Although she doesn't know this, the reason Petra enjoys smoking cigarettes is because

low doses of nicotine produce pleasurable effects by stimulating __________ receptors in the brain. a. glutamate b. dopamine c. serotonin d. acetylcholine e. GABA

Your suitemate has been sad all semester and has cried quite a bit, felt worthless and guilty and is very worried. She also has difficulty sleeping and does not eat much, which has led her to lose quite a bit of weight

What type of depression is she experiencing? major depressive disorder depressive syndrome pseudo-depression depressed mood