0.3 99-3×0.3≤X≤99+3×0.398.1≤X≤99.9 (2)已知:s=3t=3 △=3×0.3/2=0.45 z2s29×9 △20.2025 6.(1)已知:n=60p=42/60=70%2=1.96 p(1-p)_70%×30% 6% 70%-1.96×6%≤P≤70%+1.96×6%58.24%≤P≤81.76% (2)已知:z=1.96=5.8% n zp(1-p)_1.6×70%×30% 240 58% 7.(1)已知:N=2000n=200z=2 p=190/200=95% p(1-p) .75%=21.79% (2) D(1-p)_95%x5%=154% 95%-2×1.54%≤P≤95%+2×1.54%91.92%≤P≤98.08% 91.92%×2000≤NP≤98.08%×2000 1838≤NP≤1962 (3)已知:z=2△=2.31% z2p(1-p)22×95%×5% 356 (2.31%)0.3 100 9 2    n s  x 99-3×0.3≤ X ≤99+3×0.3 98.1≤ X ≤99.9 （2）已知：s=3 t=3 △=3×0.3∕2=0.45 2 2 2 9 9 400 0.2025 z s n      6.（1）已知：n=60 p=42∕60=70% z=1.96 6% 60 (1 ) 70% 30%      n p p  p 70%-1.96×6%≤P≤70%+1.96×6% 58.24%≤P≤81.76% （2）已知：z=1.96 △=5.8% 2 2 2 2 (1 ) 1.96 70% 30% 240 5.8% z p p n        7.（1）已知：N=2000 n=200 z=2 p=190∕200=95% (1 ) 95% 5% 4.75% 21.79% s  p  p     （2） (1 ) 95% 5% 1.54% 200 p p p n       95%-2×1.54%≤P≤95%+2×1.54% 91.92%≤P≤98.08% 91.92%×2000≤NP≤98.08%×2000 1838≤NP≤1962 （3）已知：z=2 △=2.31% 2 2 2 2 (1 ) 2 95% 5% 356 (2.31%) z p p n       