Question

7. [10 Points) In a study of the effect of nutritional labels on food on how much of the food is eaten, a group of university staff, graduate students, and undergraduate students were asked to evaluate a pilot episode for an upcoming TV show in a local theater. Participants were given a cold 24oz bottle of water and a bag of granola from a local health food store. They were encouraged to enjoy as much or as little of the granola as they desired. Depending on the condition randomly assigned to the participants, the granola was label as either "Regular Granola" or "Low-Fat Granola." In addition, the label indicated that the bag "contained one serving," "contained two servings," or provided no serving size information. Twenty subjects were assigned to each treatment, and their granola bags were weighed at the end of the session to determine how much granola was eaten. (a) What are the factors and the treatments? What is the response variable? (b) How many subjects does the experiment require? - (c) Is this a controlled experiment? Justify your answer. (d) Give a flowchart which outlines the design of the experiment

Answer 1

a) There are two factors namely the label of granola and the serving size information. There are 6 treatments viz,:

regular and one serving, regular and two serving, regular and no information

low fat and one serving, low fat and two serving, low fat and no information

The response variable is the weight that was measured after the end of the session.

b) The experiment requires 20*6 = 120 subjects

c) This is a controlled experiment since all other factors that could have affected the consumption of granola were controlled such as choice of the Tv show and the bottled water. Only the granola characteristics were kept variable.

d) The flow chart is given as below:

Invite students for pilot tv show screening and give them botteld, water Randomly assign granola bags to the students with different label and serving information Weigh the remaining contents of the bag for analysis