Please explain to me how to work a problem like this:

A college plans to use a new tutorial to teach the students about business ethics. As an experiment, the administrator randomly selected 15 students, and randomly assigned them to one of three groups: a Power Point presentation created by the faculty, AuthorGen Presentation created by the faculty, or a well known tutorial by the ABC company. After completing their assigned tutorial, the students are given a Business Ethics test. Using the below data at alpha = 0.01 to decide which tutorial to use?

DATA:

PowerPoint Tutorial AuthorGen Tutorial ABC Tutorial

68 85 91 87 88 79 86 82 92 91 75 83 78 86 81

Thank you.