Đề thi môn toán 1
CU 1 (2 im)a) (1 im)KiN X ~ H( 10 7 2 )SP loi A 7 X 0 1 2SP loi B 3 PX0,0667 0,4667 0,4667TNG S 10 Phõn phi s sn phm loi A cũn li trong kin Y = 7 - XY 7 6 5PY0,0667 0,4667 0,4667p dng cụng thc xỏc sut yP(Y =3) = 0,0417 0,1667 0,0833 0,2917 hay 7/24b) (1 im)LP Gii 1 mụnGii Toỏn 5 2Gii ngoi ng 9 6Gii Toỏn&NN 3 p = C(8,1)C(37,1)/C(48,2) = 0,2624 hay 37/141TNG S 48 37 (khụng gii mụn no)CU 2 (2 im)a) A, B xung khc. P(A) = 0,1 v P(B) = 0,31/ ỳng, P(A|B) = P(AB)/P(B) = 0.2/ỳng, P(AB) = P(A) + P(B) = 0,4.3/Sai, P(AB) = 04/ỳng, P(A/B/) = P(AB)/ = P() = 15/ỳng, P(A/B/) = P(AB)/ = 1 - P(AB) = 1 - (P(A) + P(B)) = 0,6.b) X, Y c lp v X ~ B( 5 0,2 ) v Y ~ H( 12 8 6 )Z = X + YP(Z 3) == P(X = 0, Y = 2) + P(X = 1, Y = 2) + P(X = 0, Y = 3) = 0,1018CU 3 (1 im)KiN YSP loi A 5 XSP loi B 3 0 1/45 2/15 1/15 2/9Th phm 2 1 2/9 1/3 5/9TNG S 10 2 2/9 2/9X ~H(10 5 2 ) TNG 7/15 7/15 1/15 1Y ~H( 10 3 2 )Z ~H( 10 2 2 ) X10 1 2P(X|Y = 0) 1/21 10/21 10/21E(X|Y = 0) = 1,43 hay 10/7CU 4 (2 im)Nc (m3)5 15 25 35 45 55S h 8 22 29 20 15 6a) Kim nh trung bỡnh 1 phớa (phớa phi) (1 im)Trung bỡnh mu = 28,00m3Phng sai mu = 179,00Phng sai mu cú c = 180,81 13,45m3Kim nh à =24,5m3Mc ý ngha =0,03 z =1,88TCK z = 2,60|z| > zbỏc b H0Mc tiờu th nc hin nay tngb) c lng trung bỡnh ca nhng h tiờu th nc bỡnh thngTrung bỡnh mu BT= 24,72m3Phng sai mu BT= 59,08Phng sai mu cú c = 59,92 7,74m3 tin cy 1 - =95% z = 1,96Sai s =1,80àBT (22,92 26,52) m3CU 5 (2 im)Kớch thc TT KT mu T s mu3000 400 290a) T l mu f = 0,7250 tin cy 1 - =97%Sai s =0,0484P(0,6766 0,7734) (2030 2321 ) sn phm A (1 im)b) chớnh xỏc =5% z = 2,24 tin cy 1 - =0,9749 hay 97,49% (1 im)CU 6TNG TH 20 23 26 29Ly mu khụng hon li, kớch thc 3, s cú C(4,3) = 4 mu, vi phõn phi phng sai mu c nh sau:S29,0 9,0 21,0 21,0 hayS29,0 21,0P 1/4 1/4 1/4 1/4 P 1/2 1/2Trung bỡnh phng sai mu E(S2) =15,0 (1 im)P(X = 0, Y = 0) + P(X = 1, Y = 0) + P(X = 0, Y = 1) + P(X = 1, Y = 1) + P(X = 0, Y = 2) + P(X = 2, Y = 0) + P(X = 1, Y = 2) + P(X = 2, Y = 1) + P(X = 0, Y = 3) + P(X = 3, Y = 0)Xỏc sut khỏch hng mua c 3 sn phm loi AXỏc sut 2 sinh viờn c chn: 1 ch gii 1 mụn v 1 khụng gii mụn no 0 1 2 TNG = =uehforum.comPDFaid.Com#1 Pdf Solutions . = 0 ,10 18CU 3 (1 im)KiN YSP loi A 5 XSP loi B 3 0 1/ 45 2 /15 1/ 15 2/9Th phm 2 1 2/9 1/ 3 5/9TNG S 10 2 2/9 2/9X ~H (10 5 2 ) TNG 7 /15 7 /15 1/ 15 1Y ~H( 10 3. ~H( 10 2 2 ) X10 1 2P(X|Y = 0) 1/ 21 10/ 21 10/21E(X|Y = 0) = 1, 43 hay 10 /7CU 4 (2 im)Nc (m3)5 15 25 35 45 55S h 8 22 29 20 15 6a) Kim nh trung bỡnh 1 phớa