4. a researcher conducts an experiment comparing two treatment conditions with 20 scores in each treatment condition. a. if an independent-measures design is used, how many subjects are needed for the experiment? b. if a repeated-measures design is used, how many subjects are needed for the experiment? c. if a matched-subjects design is used, how many subjects are needed for the experiment? gravetter, frederick j. statistics for the behavioral sciences (p. 360). cengage learning. kindle edition.

Astudy was interested in determining if eating milk chocolate lowered someone's cholesterol levels.ten people's cholesterol was measured. then, each of these individuals were told to eat 100g of milk chocolate every day and to eat as they normally did. after two weeks, their cholesterol levels were measured again. is there evidence to support that their cholesterol levels went down? how should we write the alternative hypothesis? (mud = the population mean difference= before - after)a. ha: mud = 0b. ha: mud > 0c. ha: mud < 0d. ha: mud does not equal 0