Answer
$s_{b_1}=0.00460$
Work Step by Step
$s_e=0.1121$ (item (b))
To find $s_x$:
Using the EXCEL, enter the Tar values in the column A.
In A14 enter "=STDEV.S(A1:A13)"
$s_x=7.034$
$s_{b_1}=\frac{s_e}{\sqrt {∑(x_i-x ̅)^2}}=\frac{s_e}{\sqrt {n-1}s_x}$ (see note on page 684)
$s_{b_1}=\frac{0.1121}{\sqrt {13-1}\times7.034}=0.00460$
