∑x2=a(m-1)=22024602×(20-1)=921657798 (Xx-X)=(780178-222513)=3112822026 X-X n∑x2 77098 8662426千2.101×2085553× (,野15 22026 8662426千7603111亿元)2 2 2 x n i x = − =  − =  ( 1) 22024.60 (20 1) 9216577098 2 2 ( ) (78017.8 22225.13) 3112822026 X X f − = − = 2 ^ ^ 2 2 1 ( ) f f i X X Y t n x   − +  1 9216577098 8662.426 2.101 208.5553 20 3112822026   + =8662.426 760.3111 (亿元)