If the MS between equals 10, and the MS within equals 5, then the F ratio

How can posttreatment differences occur between groups even when the treatment has no effect?

a) There are initial group differences. b) Subjects adopt an apprehensive subject role. c) Participants display reactivity. d) There were lapses in treatment integrity.

One thing shared in common by teenage mothers and older mothers who decide to raise a child without a partner is that they benefit from ____________

a. a child with an agreeable temperament b. a comfortable economic situation c. government assistance d. social support from extended family or friends