(2)价格总指数=P9x100=7170104 ∑paq 64800 4、解答:(1)n=4500×20%=900,t=2 x=∑x、,=3×8%+5×221+7×40%+9×23%+x5%=69 =∑ax-x)·3 3.9564 G2,n,3.9564,, kk=10(1-)=0(1-20%=0059 A=t.2=2×0.059=0.I8 694-0.12≤x≤6.9+0.12 6.82sx≤706 (2) 11-p1-1.)=1%m(1-20%)=.366% 0.7×0.3 An=t·Hn=2x1.366%=2.732% 70%-2.73%x≤70%+273% 6724%≤x≤7273%（2） 100% 110.74% 64800 71760 100% p q p q 0 1 1 1 =  =  =   价格总指数 4、解答：（1）n=450020%=900，t=2   =  = 3 8%+ 5  22%+ 7  40%+ 9  25%+ 11 5% = 6.94 f f x x   =  = 3.9564 f f (x - x ) 2 2  ( 1 20%) 0.059 900 3.9564 ) N n ( 1 n 2 x = − = − =   t 2 0.059 0.118 X x  =   =  = 6.94-0.12  x  6.94 + 0.12 6.82  x  7.06 （2） ( 1 20%) 1.366% 900 0.7 0.3 ) N n ( 1 n p( 1 p ) p − =  − = −  =  p = t   p = 2  1.366% = 2.732% 70%− 2.73% x  70%+ 2.73% 67.24% x  72.73%