Given below are results from the regression analysis on 40 observations where the dependent variable is the number of weeks a worker is unemployed due to a layoff (Y) and the independent variables are the age of the worker (X1), the number of years of education received (X2), the number of years at the previous job (X3), a dummy variable for marital status (X4: 1 = married, 0 = otherwise), a dummy variable for head of household (X5: 1 = yes, 0 = no) and a dummy variable for management position (X6: 1 = yes, 0 = no). The coefficient of multiple determination (R 2 j ) for the regression model using each of the 6 variables Xj as the dependent variable and all other X variables as independent variables are, respectively, 0.2628, 0.1240, 0.2404, 0.3510, 0.3342 and 0.0993. The partial results from best-subset regression are given below: Model R Square Adj. R Square Std. Error X1X5X6 0.4568 0.4116 18.3534 X1X2X5X6 0.4697 0.4091 18.3919 X1X3X5X6 0.4691 0.4084 18.4023 X1X2X3X5X6 0.4877 0.4123 18.3416 X1X2X3X4X5X6 0.4949 0.4030 18.4861

47) True or False: The sampling error can either be positive or negative.