A study has found a positive correlation between smoking ...

[HudsonKB16]

A study has found a positive correlation between smoking cigarettes and schizophrenia. What is a possible explanation for this finding?
 
  a. Emotional problems experienced during childhood cause schizophrenia.
  b. Some property of nicotine could be part of the cause of schizophrenia.
  c. The gene that carries schizophrenia also increases the potential for smoking.
  d. A fourth variable could be causing both.

Question 2

Assume that variables X and Y are significantly correlated; the third variable problem means that
 
  a. the correlation could be explained by their joint relation with some other factor.
  b. another variable must correlate with X but not Y.
  c. another variable must correlate with Y but not X.
  d. X causes Y and Y causes X.

[jgranad15]

Answer to Question 1

Answer: b.

Answer to Question 2

Answer: a.

[HudsonKB16]

TYSM

[Hdosisshsbshs]

Gracias!