Chapter 4.2, Problem 92E

To determine

To select the best answer for which design is in this experiment.

Answer to Problem 92E

Option (a) is the correct option.

Explanation of Solution

In the experiment of the previous exercise the $240$ subjects are labeled $001\text{ to 240}$ and the software assigns sixty subjects to each of the four diets. Then, subjects are randomly assigned directly into treatment groups. So, no blocks, or pairs is used. Thus, this is not an observational study because treatments are applied. Therefore, this is a simple random selection in different from random assignment. Thus, option (a) is the correct option.