A theater reports increased beverage sales during showings of The Great African Desert.We cannot conclude that the film affected beverage consumption because
A)the placebo effect was not considered.
B)only a correlation can establish causation.
C)no correlation was computed.
D)there was no control group.

Question

Quizplus · Accepted Answer

A control group is necessary to determine if the increase in beverage sales is directly related to the film or if other factors might be influencing the sales.

A Theater Reports Increased Beverage Sales During Showings of the Great