Tool abrasion and sharpening angle. A manufacturer of chisels is interested in determining how the angle at which the cutting edge is sharpened affects tool abrasion. To answer this question, engineers obtain 20 similar chisels.

They sharpen five chisels at each of 22.5, 25, 27.5, and 30 degrees. Then they measure the amount of abrasion (rated on a scale of 1 to 10, with 10 being the worst) after cutting several mortises (square holes) in 3/4-inch hard maple boards.

(a) The individuals studied in this experiment are not people. What are they?

Chapter 5 Exercises 97

(b) What is the explanatory variable, and what values does it take?

(c) What is the response variable?

AppendixLO1