A high correlation between two variables does not always mean that changes in one cause changes in the other. The best way to get good evidence that cause-and-effect is present is to
A) select a simple random sample from the population of interest.
B) arrange the data in a two-way table.
C) carry out a randomized comparative experiment.
D) make a scatterplot and look for a strong association.
E) make a histogram and look for outliers.

Question

Quizplus · Accepted Answer

The best way to establish causality is through a randomized comparative experiment where one variable is manipulated and the other is observed for any changes. This helps to control for other factors that may be influencing the relationship between the two variables. Simply observing a strong correlation or association between two variables does not provide sufficient evidence for causality.

A High Correlation Between Two Variables Does Not Always Mean