Using 959 members of the September 1968 freshman class of Mesa Community College, Arizona, this study analyzed the relationship of American College Testing Program (ACT) test battery placement scores to junior college grade point averages (GPA) for freshmen entering as adults and for those entering as recent high school graduates. Recent graduates were under 19 at registration time, and obliged to take the ACT (if carrying 10 semester hours or more); adult counterparts were 21 or over. These groups were subdivided by sex and curriculum (educational background). There was a significantly greater relationship between ACT scores and GPA for young freshman students than for the adult group. As for sex, significant differences emerged between young and adult freshman men, but not between the two groups of freshman women. As for educational background, ACT and GPA correlation coefficients differed significantly between recent academic and nonacademic high school graduates, but not between the adults and recent graduates as such, or between adult academic and adult nonacademic graduates. (Author/LY)