In a study examining the effects of time of day (morning or afternoon) and temperature (cool, normal, or warm) on worker productivity, how many main effects are possible?

In the United States, almost ___________ of children are enrolled in some type of childcare arrangement outside of the home, which either explicitly or implicitly teaches skills that enhance intellectual and social abilities

a. 25% c. 50% b. 33% d. 75%

Who is MOST likely to mention intimacy as an important characteristic in a best friend?

A) a second-grade boy B) a second-grade girl C) a sixth-grade boy D) a sixth-grade girl