Comparing weight-loss treatments. Twenty overweight females have agreed to participate in a study of the effectiveness of 4 weight-loss treatments:

A, B, C, and D. The researcher first calculates how overweight each subject is by comparing the subject’s actual weight with her “ideal” weight. The subjects and their excess weights in pounds are Birnbaum 22 Hernandez 25 Moses 34 Smith 42 Brown 34 Jackson 33 Nevesky 28 Stall 33 Brunk 30 Kendall 28 Obrach 30 Tran 35 Cruz 25 Loren 32 Rodriguez 30 Wilansky 29 Deng 24 Mann 39 Santiago 27 Williams 35 The response variable is the weight lost after 8 weeks of treatment. Because a subject’s excess weight will influence the response, a block design is appropriate.

(a) Arrange the subjects in order of increasing excess weight. Form 5 blocks of 4 subjects each by grouping the 4 least overweight, then the next 4, and so on.

(b) Use Table A to randomly assign the 4 subjects in each block to the 4 weightloss treatments. Be sure to explain exactly how you used the table.

AppendixLO1