solve the following one

2. Suppose the manager of HRD would like to examine the relationship between increment in the salary (Y) BDT and years of experience( X)among the employees with different job categories (X2) such as clerical, custodial, and managerial. The data on 56 employees on these variables were obtained. Two dummy variables were created for the categorical independent variable X2 as D1=1 if he/she is doing custodial job and 0 for otherwise and Do=1 if s/he is doing managerial job and 0 for otherwise.. The least squares estimate are given below: Y = 120 + 10.3X1 + 20.8D1 + 32.4D2 with SE(81) = 0.876; SE(82) = 3.26 SE(#2) = 3.87 and SST=12036, SSE=3050 (a) Interpret the estimate of the each of the coefficient corresponding to X1, D, and D2. (b) What is the difference in the estimated average increment for two employees both doing managerial job whose experience differ by 5 years? (c) Is there any difference in increment for two employees with the same years of experience one who is doing Custodial and the other who is doing managerial job? Give reasoning of your answer. (d) Test whether the experience has positive effect on increment or not at 2.5% level of significance