12. A study was made on the effect of temperature (X) on the yield (Y ) of a chemical process. The following data (coded) were collected (from Draper and Smith, 1981, used with permission):

X: −5 −4 −3 −2 −1 0 1 2 3 4 5 Y: 1 5 4 7 10 8 9 13 14 13 18 15.3 Unbiased Estimator of σ2 637

(a) Construct a scatter diagram for these data.

(b) Fit a simple linear regression model to these data considering X an independent variable and Y a response variable. Assume that the simple linear regression model is appropriate for these data.

(c) Using

(b) record the least-squares estimates of the regression coefficients.