develop the estimated regression equation to predict the repair time given the number of months since the last maintenance service, the type of repair, and the repairperson who performed the service. assume that if the type of repair is electrical and if dave newton performed the service. enter negative value as negative number. round your answers to three decimal places. b. at the level of significance, test whether the estimated regression equation developed in part (a) represents a significant relationship between the independent variables and the dependent variable. compute test statistic (to 2 decimals).