State whether the investigator should use independent samples, repeated measures, or matched samples:

a. An investigator wants to know whether men or women select larger entrée portions in a cafeteria food line. He watches men and women as they go through a food line and rates the relative size of their food portions.

b. An investigator wants to know whether tutoring helps improve students’ writing skills. He rates students’ essays before they receive tutoring and again after they receive tutoring.