When two variables are perfectly correlated, _____. a. one ...

[Charlie]

When two variables are perfectly correlated, _____.
 
  a. one must cause the other, but we don't know which is the cause and which is the effect
  b. neither one causes the other
  c. it is certain that a third factor is causing both variables to co-vary
  d. none of these

Question 2

With the exception of division, one can perform all mathematical operations on a ratio scale.
 
  Indicate whether the statement is true or false

[jesse.fleming]

Answer to Question 1

D
Any either one of the variables might cause the other, or a third factor might be causing both. We simply do not know anything about causality given a correlation, even a perfect one.

Answer to Question 2

F

[Charlie]

Gracias!

[LVPMS]

Thanks for the timely response, appreciate it