Janet is testing the effectiveness of four different plant foods. she plants four identical seeds in four identical pots, supplying each with a different type of plant food. after six weeks she finds that the four plants have grown to different heights.
can janet conclude that food w is the most effective of the four plant foods?
a. yes; since the plant that was fed food w grew to the greatest height, the only explanation is that food w is the most effective.
b. no; janet needs to test many more different types of plant food before she can reach that conclusion.
c. yes; 18 inches is the tallest a plant of that species has ever grown.
d. no; janet needs to conduct repeated trials on many different plants before she can make that conclusion.