一2 = ] + 0.99152-2x0.696 X 0.9915 = 0.6029 所以与简单估计量比,比率估计量的精度提高了1-0.6029=39.71%. 5.6 记总产量为匕总播种面积为X 1-f1-10/140 X = 460 N=140 /?= 10 — =——= 0.09286 n10 )'=£月=12600工=工玉=29.7 y = 1260无=2.97 ...