Question......

Looking at how hourly wage (Dependent variable, wage) could be affected by job tenure (Independent variable, tenure=number of years stayed in that position), we have performed an linear regression, and the results are printed below: . reg wage tenure Source 55 df MS Number of obs = 2,231 F(1, 2229) = 72.66 Model 2339.38077 1 2339.380?7 Prob > F = 0.0000 Residual 71762.4469 2,229 32.1949066 Rsquared = 0.0316 Adj R-squared = 0.0311 Total 74101.8276 2,230 33.2295191 Root MSE = 5.6741 wage Coef. Std. Err. t P>|t| [95% Conf. Interval] tenure .1050747 .0218054 0.52 0.000 .1431133 .2286357 _con5 6.681316 .1772615 37.69 0.000 6.333702 7.023931 a) \"That is the total variance (or proportion of explained variation) explained? 13) What statistical conclusion should you make about the effect of the job tenure on average hourly wage? (hint: interpret the coefcient on Tenure. c) Based on the regression output, on average, what's the average hourly wage if someone stayed in her job for 10 years? (hint: write out the linear equation and plug in intercept and coefcient to calculate the estimate. d) Other people argue that people's race, education attainment, how many hours someone works each week, and total years of experience might also have an impact on hourly wage. So we have included additional independent variables in the linear regression analysis. The output is printed below. By looking at the new regression output, explain which variables are statistically signicant at 95% level. Can we still be able to use Tenure as a predicator to estimate hourly wage? Explain why. . reg wage tenure race eollgrad hours ttl_exp Source 55 df HS Number of obs = 2.22? F[5. 2221} = 72.38 Model 10330.0026 5 2034.13651 Prob > F = 0.0000 Residual 63649.923 2,221 28.6502296 Rsquared = 0.1401 Adj R-squared = 0.1302 Total 74020.0106 2.226 33.2520349 Root MSE = 5.3533 wage Coef. Std. Err. t P>|t| [95% Conf. Interval] tenure .0321536 .0252311 1.2? 0.203 .01?3254 .0816326 race .91T8725 .239?636 -3.83 0.000 -1.33805? .4476803 collgrad 3.11444? .2694531 11.50 0.000 2.500021 3.642373 hours .0502641 .011163 4.50 0.000 .020373 .0?21552 ttl_exp .2515364 .0306305 0.21 0.000 .1914533 .3116194 _cons 3.013562 .5610377 5.3? 0.000 1.913349 4.113116 points)