Lxx=∑(xi-x*)^2

Lxy=∑(xi-x*) (Yi -y*)

b=Lxy/Lxx，a=y*-bx*

y^=a+bx

2.y^(0)=a+bx(0)(x(0)=80)

The confidence interval of the cost of a certain place of origin is (y (0)-δ, y (0)+δ).

δ=√{fα( 1,n-2)σ^2[ 1+ 1/n+(x(0)-x*)/∑(xi-x*)^2]}

σ 2 = ∑ (yi-y I) 2/(n-2) (where y I = a+bxi) 1. Replace the sample mean with x* and calculate with the following formula.

Lxx=∑(xi-x*)^2

Lxy=∑(xi-x*) (Yi -y*)

b=Lxy/Lxx，a=y*-bx*

y^=a+bx

2.y^(0)=a+bx(0)(x(0)=80)

The confidence interval of the cost of a certain place of origin is (y (0)-δ, y (0)+δ).

δ=√{fα( 1,n-2)σ^2[ 1+ 1/n+(x(0)-x*)/∑(xi-x*)^2]}

σ 2 = ∑ (yi-y I) 2/(n-2) (where y I = a+bxi)