In equal n's one-way ANOVA, MSerror equals the mean of the k within-group variances.

Requiring participation in a psychological experiment for course credit is ethical if:

a. alternative ways of obtaining course credit are available. b. the participants has the right to withdraw without penalty. c. the participant has given informed consent. d. all of these

Jessica and Dawn are identical twins who were raised apart for most of their lives. When in their twenties they independently developed similar interests, including a strong interest in ice skating. This observation is consistent with the idea that

a. their interest in ice skating was genetically determined. b. some aspect of their common genotype caused them to pick similar niches. c. their interest in ice skating was environmentally determined. d. their interest in ice skating is neither genetically nor environmentally determined.