選択した画像 ƒƒ“ƒY ƒp[ƒ} ƒIƒXƒXƒ 480465-Y=p x q^x-1
P XiYi = 1 SSX Y (P X2 i) − P P i i XiYi −nX Y = 1 SSX Y (P X2 i)− n 2) P iYi SPXY = 1 SSX YSS X −SPXYX SPXY = " Y − SPXY SSX X SPXY SSX # = b0 b1 ;To see a counterexample, consider P(x,y) = \person x is in location y" Then 8x9yP(x;y) says \Everyone is located somewhere", while 9x8yP(x;y) says \Someone is located everywhere" These clearly don't mean the same thing!Where SSX = X X2 i −nX 2 = X (Xi −X )2 SPXY = X XiYi −nX Y = X (Xi −X )(Yi −Y ) All we have done is to write the same old formulas for b0 and b1 in a fancy new format See NKNW page 199 for details Why have we bothered to do P X Y Example Y=p x q^x-1