Question

A psychologist is interested in the relationship between color of food and appetite. To explore this relationship, the researcher bakes small cookies with icing of one of three different colors (green, red, or blue). The researcher offers cookies to subjects while they are performing a boring task. Each subject is run individually under the same conditions, except for the color of the icing on the cookies that are available. Six subjects are randomly assigned to each color. The number of cookies consumed by each subject during the 30-minute session were recorded. a. What is the factor variable in this study, how many levels does it have, and what are they? b. What is the dependent variable in this study? c. Assuming a one-way ANOVA is used to evaluate the data collected for this study, state the null and alternative hypotheses using statistical notation, and then write them out in sentence form with respect to the variables in this study.

Answer 1

a.

The factor variable in this study is color of the icing on the cookies. There are 3 levels - green, red, or blue.

b.

The dependent variable in this study is number of cookies consumed.

c.

Let be the mean number cookies consumed with green, red, or blue icing respectively.

Null hypothesis H0:

Alternate hypothesis H1: or or

Null hypothesis H0: Number of cookies consumed for all three different colors are equal.

Alternate hypothesis H1: At least one of means number cookies consumed is different.