Question

three students test the effect of fertilizer on bean plant growth. each student conducts one trial. they plant 10 bean seeds in each of three large pots of soil with different amounts of fertilizer. after two weeks, they measure the heights of the plants in each pot. then they find the average height for each amount of fertilizer. the table summarizes the results of the experiment.
effect of fertilizer on height of bean plants

amount of fertilizer	average height after 2 weeks (cm)
none	18.9	21.5	40.2
a little	19.5	32.7	39.7
a lot	34.3	33.2	16.5

which statement describes a pattern shown in the data?
a. the data from trial 1 are inconsistent with the data from trials 2 and 3.
b. the trend in the data for trial 1 shows that plants grow taller if given more fertilizer.
c. the trend in the data for trial 2 shows that more fertilizer causes less growth.
d. the data for the average heights of the plants in all three trials

Explanation:

For option A, there is no clear - cut evidence of inconsistency just by looking at the values. For option B, in trial 1, the values don't show a clear increase in height with more fertilizer. For option C, in trial 2, as the amount of fertilizer goes from none to a little to a lot, the average height first increases (from 21.5 to 32.7) and then decreases (to 33.2), indicating more fertilizer can cause less growth. For option D, there is no clear overall pattern for all three trials together regarding average heights.

Answer:

C. The trend in the data for trial 2 shows that more fertilizer causes less growth.