* PS8.1, using DATA3-11, for Examples 8.1 and 8.2 read(data3-11) SALARY YEARS genr LNSALARY=log(SALARY) * graph for Figure 8.2 and Example 8.1 plot LNSALARY YEARS genr YRS2 = YEARS*YEARS * estimate basic log quadratic model for Example 8.2 ols LNSALARY YEARS YRS2 / pred=yhat resid=uhat genr usq=uhat*uhat * graph estimated residual variance against YEARS and yhat plot usq YEARS plot usq yhat stop