For each of the following studies, say whether you would use a t test for dependent means or a t test for independent means.
(a) A researcher randomly assigns a group of 25 unemployed workers to receive a new job skills program and 24 other workers to receive the standard job skills program, and then measures how well they all do on a job skills test.
(b) A researcher measures self-esteem in 21 students before and after taking a difficult exam.
(c) A researcher tests reaction time of each member of a group of 14 individuals twice, once while in a very hot room and once while in a normaltemperature room.