Refer to Exercise 11.9.

a. Find the least- squares estimates of the slope and intercept in the output.
b. What does the sign of the slope indicate about the relation between the speed of the drill and bit lifetime?
c. Compute the residual standard deviation. What does this value indicate about the fitted regression line?
In exercise

Transcribed Image Text:

Regression Analysis Lifetime versus Dri11speed The regreasion equation is Lifetime # 6.03-0.0170 Dr111speed Fredictor Constant Driiiapeed -0.017000 0.004999 3.40 0.003 Coet SE Coef 6.0300 0.5195 11.61 0.000 g 0.632 368 R-Sq 39.1% R-Sq (adj) 35.74 " . Analysis ot Variance Source Regression Residual Eror 18 7 190 0.3999 Total DF MS 1 4.6240 .6240 11.56 0.003 19 11.8220 Unusual Observations Obs Driilspeed LifeTineFLE SE Fit Residual St Resid 3.900 5.010 0.245 60 -1.210 -2.08R R denotes an observation vith a iarge standaraize reidual 60 0 60 60 80 0 80 80 100 100 y 4.6 38 4.9 45 4.7 58 5.5 5.4 5.0 4.5 x 100 100 120 20 120 120 140 140 140 140 y 3.2 4.8 4. 45 4.0 8 3.6 3.0 3.5 3.4