Answer
$s_e=0.5102$
Work Step by Step
$ŷ =-0.1049x+3.859$
$s_e=\sqrt {\frac{Σ(y_i-ŷ_i)^2}{n-2}}=\sqrt {\frac{[4.00-(-0.1049\times1+3.859)]^2+[3.35-(-0.1049\times2+3.859)]^2+[3.50-(-0.1049\times2+3.859)]^2+...+[3.74-(-0.1049\times9+3.859)]^2+[3.75-(-0.1049\times9+3.859)]^2+[1.71-(-0.1049\times11+3.859)]^2}{38-2}}=0.5102$
