Answer
$s_e=2.450$
Work Step by Step
$ŷ =2.635x+29.70$
$s_e=\sqrt {\frac{Σ(y_i-ŷ_i)^2}{n-2}}=\sqrt {\frac{[36.1-(2.635\times2+29.70)]^2+[34.2-(2.635\times2+29.70)]^2+[31.1-(2.635\times2+29.70)]^2+[36.3-(2.635\times3+29.70)]^2+[39.5-(2.635\times3+29.70)]^2+[41.5-(2.635\times4+29.70)]^2+[38.6-(2.635\times4+29.70)]^2+[45.6-(2.635\times5+29.70)]^2+[44.8-(2.635\times5+29.70)]^2+[44.6-(2.635\times5+29.70)]^2+[49.8-(2.635\times6+29.70)]^2+[43.2-(2.635\times7+29.70)]^2+[47.9-(2.635\times7+29.70)]^2+[51.4-(2.635\times8+29.70)]^2+[48.3-(2.635\times8+29.70)]^2+[50.9-(2.635\times8+29.70)]^2+[52.2-(2.635\times9+29.70)]^2+[51.3-(2.635\times9+29.70)]^2+[55.6-(2.635\times10+29.70)]^2+[59.5-(2.635\times10+29.70)]^2}{20-2}}=2.450$
