Twelve different automobiles were tested at a speed of 15 miles per hour for stopping distances. The data, in feet, are shown below.

15, 18, 18, 18, 20, 22, 24, 24, 24, 25, 26, 26

1. Find the five-number summary and the mean for the stopping distances (You MUST show the hand calculations. That is, type up your work within Canvas. Using MINITAB is not acceptable).
2. Based only on the information in part (1), what shape would you expect to see if you produced a histogram? Explain.
3. Are there any outliers in the dataset? Justify with calculations you lean in the class. If there are outliers, identify them.
4. Suppose the tire brand (Brand 1 and Brand 2) was observed for each auto and the stopping distances for each brand are shown below:

Tire Brand 1: 18, 18, 18, 20, 24

Tire Brand 2: 15, 22, 24, 24, 25, 26, 26

Suppose the researcher would like to see if the stopping distance of an automobile is different for the two tire brands. What is the response variable and what type of variable is it? What is the explanatory variable and what type of variable is it?