Chapter 13.2, Problem 20E

The paper “The Effects of Split Keyboard Geometry un Upper Body Postures” (Ergonomics [2009]: 104–111) describes a study to determine the effects of several keyboard characteristics on typing speed. One of the variables considered was the front-to-back surface angle of the keyboard. Minitab output resulting from fitting the simple linear regression model with x = Surface angle (degrees) and y = Typing speed (words per minute) is given below.

1. a. Assuming that the basic assumptions of the simple linear regression model are reasonably met, carry out a hypothesis test to decide if there is a useful linear relationship between x and y. (Hint: See Example 13.5.)
2. b. Are the values of s_e and r² consistent with the conclusion from Part (a)? Explain.