Answer
$s_e=269.049$
Work Step by Step
$ŷ=137.7x−4599$
$s_e=\sqrt {\frac{Σ(y_i-ŷ_i)^2}{n-2}}=\sqrt {\frac{[1168-(137.7\times40−4599)]^2+[1170-(137.7\times40−4599)]^2+[1494-(137.7\times46−4599)]^2+[1500-(137.7\times46−4599)]^2+[1559-(137.7\times46−4599)]^2+[2700-(137.7\times52−4599)]^2+[2600-(137.7\times55−4599)]^2+[3890-(137.7\times60−4599)]^2+[4478-(137.7\times65−4599)]^2}{9-2}}=269.049$