Question

what are the effects of low-fat food labels on food consumption? do people eat more of a snack food when the food is labeled as low-fat? the answer may depend both on whether the snack food is labeled low-fat and whether the label includes serving-size information. an experiment investigated this question using university staff, graduate students, and undergraduate students at a large university as subjects. subjects were asked to evaluate a pilot episode for an upcoming tv show in a theater on campus and were given a cold 24-ounce bottle of water and a bag of granola from a respected campus restaurant called the spice box. they were told to enjoy as much or as little of the granola as they wanted. depending on the condition randomly assigned to the subjects, the granola was labeled as either
egular rocky mountain granola\ or \low-fat rocky mountain granola.\ below this, the label indicated \contains 1 serving\ or \contains 2 servings,\ or it 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.
how many subjects does the experiment require?
number of subjects:

Explanation:

Step1: Identify the number of conditions

The granola is labeled in three ways: "Contains 1 Serving", "Contains 2 Servings", or no serving - size info. And also labeled as "Regular" or "Low - Fat", so there are \(3\times2 = 6\) different treatment groups.

Step2: Determine the number of subjects per group

We are told that twenty subjects were assigned to each treatment.

Step3: Calculate the total number of subjects

To find the total number of subjects, we multiply the number of treatment groups by the number of subjects per group. So the total number of subjects \(N=6\times20 = 120\).

Answer:

120