(Continuation from Chapter 4, Number 3)You Have Obtained a Sub-Sample $\widehat {E a m }$

Essay

(continuation from Chapter 4, number 3)You have obtained a sub-sample of 1744 individuals from the Current Population Survey (CPS)and are interested in the relationship between weekly earnings and age. The regression, using heteroskedasticity-robust standard errors, yielded the following result: $\widehat {E a m }$ = 239.16 + 5.20×Age , R² = 0.05, SER = 287.21.,
(20.24)(0.57)
where Earn and Age are measured in dollars and years respectively.
(a)Is the relationship between Age and Earn statistically significant?
(b)The variance of the error term and the variance of the dependent variable are related. Given the distribution of earnings, do you think it is plausible that the distribution of errors is normal?
(c)Construct a 95% confidence interval for both the slope and the intercept.