:1. Diagram ?? has two panels, each of which represents a scatter diagram. The panel on the left represents income and education for individuals in three geographic regions, labelled A,B,C. Each individual is marked by the letter showing his region of residence. The panel on the right shows the averages for each region. This shows that one must be cautious about ecological correlations (correlations based on rates or averages) because
a. such a correlation can ruin a perfectly good bowl of alphabet soup.
b. a correlation based on individuals may be only moderate, while one based on averages may be close to 1. c. an ecological correlation can be excessively beneficial to the enviroment.
d. as shown by the two panels, a correlation based on averages may be only moderate, while one based on individuals may be close to 1.
e. replacing individuals by averages doesn't affect the correlation coefficient.
: Exactly 1 of the five choices a,b,c,d, and e results in a true statement.