The following output summarizes the fit of an analysis of covariance to the data in Exercise 36. The variable D denotes a dummy variable, with D = + for values colored green and 0 otherwise.
(a) What is the interpretation of the coefficient of D in the fit of this multiple regression? Use the context of the analysis in your answer.

(b) For what size production run does it appear that the trained employees (shown in green with D = 1) appear more productive than the employees who did not receive training 1red, D = 02? If one group is always better than the other, say so.

Transcribed Image Text:

Estimate Std Error t-Statistic p-Value 28.41 0.0001 47.26 <0.0001 28.22 <0.0001 Dx Units-0.4571 0.0205 22.30 0.0001 Term Intercept Units 29.4379 0.7083 40.5328 1.0362 0.0150 1.4364