49. The time to failure of a machine component is related to the operating voltage

(x1), the motor speed in revolutions per minute (x2), and the operating temperature (x3). A designed experiment is run in the research and development laboratory, and the following data, where y is the time to failure in minutes, are obtained.

(a) Fit a multiple regression model to these data.

(b) Estimate the error variance.

(c) Determine a 95 percent confidence interval for the mean time to failure when the operating voltage is 125, the motor speed is 900, and the operating temperature is 160.

Transcribed Image Text:

y x1 x2 x3 2,145 110 750 140 2,155 110 850 180 2,220 110 1,000 140 2,225 110 1,100 180 2,260 120 750 140 2,266 120 850 180 2,334 120 1,000 140 2,340 130 1,000 180 2,212 115 840 150 2,180 115 880 150