Answer
(b).
Work Step by Step
We can find the slope $b$ in the row "appraised" and the column "Coeff," thus $b=1.2103$.
We can find standard error of the slope $b$ in the row "appraised" and the column "SE Coeff", thus $SE_b=0.154$.
The degree of freedom is the sample size minus $2$: $df=n-2=47-2=45\gt40$.
The critical value is given in the row $df=40$ and in the column with $c=0.95$ of the table. Thus $t=2.021$.
The confidence interval is then: $b\pm tSE_b=1.2103\pm2.021\cdot0.154=1.2103\pm0.3112$, thus the answer is (b).
