chapter 1

Chapter 13: Nonlinear and Multiple Regressione.Normal Plot of Standard ResidualsStandard Residuals vs x2211std res0stdresid0-1-1-1 0 1%iles20 30 40 50xThe normal plot gives no indication to question the normality assumption, and theresidual plots against both x and y (only vs x shown) show no detectable pattern, so wejudge the model adequate.67.a. For a one-minute increase in the 1-mile walk time, we would expect the VO 2 max todecrease by .0996, while keeping the other predictor variables fixed.b. We would expect male to have an increase of .6566 in VO 2 max over females, whilekeeping the other predictor variables fixed.c. y ˆ = 3.5959 + .6566( 1) + .0096( 170) −.0996( 11) −.0880( 140) = 3. 67residual is y ˆ = ( 3.15 −3.67) = −.52 .SSE30.10332d. R = 1−= 1 − = .706,or 70.6% of the observed variations inSST102.3922VO 2 max can be attributed to the model relationship.e. β = β = β = β 0H will be rejected in favor of H :0:1 2 3 4=β1,..., β4≠ 0 , if f ≥ F . 05,4,15= 8. 25. Withfa. Theat least one among(.706)4( )= 9.005 ≥ 8. 25 , so H o1 .706= −is rejected. It appears that the model specifies a useful relationship between VO 2 max andat least one of the other predictors.15430