A sample of 100 people is classified by gender (male/female) and by whether or not they are registered voters. The sample consists of 80 females and 20 males, and has a total of 60 registered voters. If these data were used for a chi-square test for independence, what is the expected frequency for males who are registered voters?

Humans demonstrate habituation as early as ______.

A. 19-21 weeks' gestation B. 22-24 weeks' gestation C. 3 days old D. 5 days old

Causal inferences are difficult to predict between personality and drugs because:

a. There is no connection between personality and drugs b. There is a direct connection between personality and drugs c. There is an indirect connection between personality and drugs d. The relationship between personality and drugs is unobservable