Donna is calculating the correlation coefficient between two continuous variables. Which correlation coefficient should Donna use?

Which of the following statements is supported by research on childhood injuries?

A) U.S. children from advantaged families are at considerably greater risk for injury than children in Western Europe. B) Childhood injury deaths in developing nations are 1.5 times as high as those in developed countries. C) Safety devices, such as car seats and bicycle helmets, are readily available in developing nations, but they are rarely used by parents. D) Contrary to popular belief, girls are more likely to be injured than boys during play.

The idea that people choose mates on the basis of particular characteristics is called

a. directional selection. b. assortative mating. c. selective mating. d. intuitive mating.