Coffee is a leading export from several developing countries. When coffee prices are high, farmers often clear forest to plant more coffee trees. Here are data on prices paid to coffee growers in Indonesia and the rate of deforestation in a national park that lies in a coffee-producing region for five years.
Price(cent per pound) Deforestation %
30 0.58
32 1.6
54 1.72
70 1.79
74 3.25
Make a scatterplot. (Do this on paper. Your instructor may ask you to turn this in.) Which is the explanatory variable? What kind of pattern does your plot show?
A. Price is the explanatory variable. The plot shows a negative linear association.
B. Price is the explanatory variable. The plot shows a positive linear association.
C. Price is the explanatory variable. The plot shows no linear association.
D. Deforestation is the explanatory variable. The plot shows a positive linear association.
Find the correlation r step-by-step. That is, find the mean and standard deviation of the two variables. Then find the five standardized values for each variable and use the formula for r.