What is the arithmetic average of a group of scores?

At the beginning of the __________ stage, an infant centers more on action rather than thought

a) preoperational b) formal operations c) sensorimotor d) concrete

In Patterson's observations of family interactions in troubles and typical homes, he noted that

a. in typical families, children responded to parental correction or discipline with aggression or anger b. in troubled families, episodes of parent-children interaction often became increasingly hostile and aggressive c. in typical families, episodes of parent-children interaction at dinner time frequently included loud arguments d. in troubled families, negativity and emotionality tended to de-escalate over the course of parent-child interaction concerning discipline