Problem: Adolescent obesity. Adolescent obesity is a serious health risk affecting more than 5 million young people in the United States alone. Laparoscopic adjustable gastric banding has the potential to provide a safe and effective treatment. Fifty adolescents between 14 and 18 years old with a body mass index higher than 35 were recruited from the Melbourne, Australia, community for the study. Twenty-five were randomly selected to undergo gastric banding, and the remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. All subjects were followed for two years and their weight loss was recorded.7
Requirement:
(i) Outline the design of this experiment, following the model of Figure 9.3 (page 229). What is the response variable?
(ii) Carry out the random assignment of 25 adolescents to the gastric-banding group, using the Simple Random Sample applet, other software, or Table B, starting at line 130.