"A researcher wishes to determine the effects of an outdoor adventure summer camp on the self-concept of inner-city boys. Boys are randomly assigned to the summer camp and to a control situation. The experimental treatment is for three months. A secondary purpose is to see if age (ages 6, 9, and 12) affects the relationship of the camp effects and self-concept." The categorical variable is:

This term refers to the number of people per unit area (usually a kilometer or a mile). this could refer to the number of people per square mile in a city, a county, a province, a state, or a nation.

Which term describes a possible explanation of, or answer to, a scientific question that is based on prior knowledge or research and that is testable?

Which of the following is an example of proximodistal pattern of growth? (a) abbey learning to sit first before learning to stand or crawl (b) alex learning to move his eyes before learning his first words (c) colin learning to stare at moving objects before trying to touch them with his hands (d) polly learning to grab the objects with her whole hands before learning to pick them up with her fingers