Exercise 2 refers to a t test. What is a t test? Why is the letter t used? What is unrealistic about the z test methods in Part 2 of this section?

Exercise 2:

If we are using the sample data from Exercise 1 for a t test of the claim that the population mean is greater than 90 sec, what does df denote, and what is its value?

Exercise 1:

Twelve different video games showing alcohol use were observed. The duration times of alcohol use were recorded, with the times (seconds) listed below (based on data from “Content and Ratings of Teen-Rated Video Games,” by Haninger and Thompson, Journal of the American Medical Association, Vol. 291, No. 7). What requirements must be satisfied to test the claim that the sample is from a population with a mean greater than 90 sec? Are the requirements all satisfied?