When two variables vary in the same direction, what type of correlation has occurred?

A researcher is interested in the changing nature of sex roles in contemporary society. If she were to employ an archival analysis, what would she be most likely to do?

a. record how boys and girls are portrayed in children's books b. observe both men and women in "non-traditional" occupations c. interview both male and female doctors to determine how they are treated by colleagues d. participate in the daily activities of a family in which the woman works and the man stays home

__________ hormones can readily penetrate cell membranes because their molecules are small and fat soluble

Fill in the blank with the appropriate word.