Mr. Jefferson, a farmer-philosopher-president, has a vineyard. On his fields 5-10-5 fertilizer (5 percent nitrogen, 10 percent potash, 5 percent potassium) causes a 10 percent increase in yield of corn. 10-20-10 fertilizer causes a 15 percent increase in yield of corn. Suppose both fertilizers were applied by Mr. Jefferson (whose philosophy is, "If a little bit does a little good, a whole lot will do a whole lot of good"). Which outcome below would indicate if there was no interaction?
A) 10 percent increase
B) 15 percent increase
C) either a 10 percent increase or a 15 percent increase
D) 25 percent increase.

Question

Quizplus · Accepted Answer

If there was no interaction between the fertilizers, their effects would simply add up, leading to a total increase of 25 percent (10 percent from the first fertilizer plus 15 percent from the second).

Mr Jefferson, a Farmer-Philosopher-President, Has a Vineyard