概率论与数理统计第三课后答案习题.doc

1、leading cadres awareness of right in place, study the party Constitution and party rules, series of speeches can make proper effect. Party cadres to “two“ lead by example, to lead by example we must change our mind, recognizing that “two“ is important. First, learn the Communist Party Constitution P

2、arty rules, learning learning series important speech by General Secretary can enhance theory. With the “third revolution“ the rise of rapid changes in our life are feeling, the Communists should adhere to the theory of confidence will continue to learn from the voices of the times, the times, in tu

3、rn, will have new requirements for leading party cadres. “Two“ is the most basic meaning of members all mastering the core theory and the most advanced weapons theory, complement the spirit of calcium. Secondly, the Communist Party Constitution Party rules, learning learning series important speech

4、by General Secretary be able to firmly build the ideological foundation. Under the impact of multiple values, the “two“ is to help cultivate independent judgment in numerous miscellaneous multiple concepts, so that the majority consensus of party members, the important magic weapon of the party with

5、 the resonance frequency. Finally, the Constitution of the Communist Party, party rules, learning learning series important speech can stand crowds, General Secretary position. Now, some grass-roots work in the “the old way didnt work, hard way cannot, the new approach would not“ phenomenon, sometim

6、es due to a mass of party members and cadres not understanding, does not meet. In fact, the mass “convincing“ and “identity“Behind are likely to be party members and leading cadres themselves ignoring beliefs held, resulting in lack of persuasion and sense of identity. “Two“ is in fact guaranteed pa

7、rty cadres work, an important prerequisite for convincing the masses. Bacon said it well: “practical men can handle individual matters, but looking at the whole operation globally, but only man can do to knowledge. “Giving up“ two “effective, must first raise awareness of leading cadres of party mem

8、bers, as party members learn real responsibility“ to know “to“ music “,“ good “changes, in parallel with the ground, do not forget to also answer the antenna, draw catches on meteorology, which sit between heaven and Earth which melds together the dreams of practicing Communist. Members cadres shoul

9、d in “two learn a do“ in the based post do contribution in all members in the carried out “learn Constitution Party rules, and learn series speech, do qualified members“ learning education, this is following party of mass line education practice activities and “three strict three real“ topic educati

10、on zhihou, deepening party education of and once important practice, is promoted “three strict three real“ topic education from “key minority“ to all members expand, and from concentrated education to regular education extends of important initiatives. Vast numbers of party members and cadres in the

11、 course of two, should bebased on their actual, striving to be “learning“ and “done“ markers. Strengthening theoretical study, belief and faith. Theory is an action guide, only theoretical knowledge in place, to unity, action can consciously. Constitution is the fundamental law of the party, party r

12、ules are party must follow the General rules. Studying and implementing the party Constitution Party rules and a series of important speech, General Secretary, is a guide to persisting and developing socialism with Chinese characteristics, is a basic work of strengthening the partys construction, bu

13、t also each and every Communist Party Members obligations and solemn responsibility. These important content, for each party, must know would believe will do both. WeGeneral Secretary of the party Constitution, a series of remarks with, and hold, grasp the real “learning“ that basis, based on the Co

14、nstitution speak to issue, in accordance with the series changed the problem. Second, disciplined in line, to become law-abiding model. Is not no rules. If there is no iron discipline, party members and cadres will become a mess, it will lose its fighting strength and vitality, purity and naturally

15、much less advanced. By “two“ education, party members and cadres to keep the “bottom line“, not the more “red lines“, consciously practice the “three Suns“ and consciously act according to the Constitution, party rules, remains a political force, to perform party oath, a tree of its own image. Three

16、 is the loyal, dare to play and play to party members. Learning is the Foundation, is the key to development is the goal. “Two“ main objective is to let the majority of the play to the exemplary role of party members and cadres, party Constitution, party rules to examine. To use new criteria to guid

17、e our behavior. Through education, the ideal and conviction, keep in mind that membership, learn, learn, learn go play a vanguard and exemplary role, the courage to play as, and always maintain the pioneer, pioneering and enterprising spirit, and constantly improve our own capacity and level of serv

18、ice, according to positions and make contributions. Hearts change, lead more strict “began in the know, know as Luke Skywalker“, “two“ activities, be qualified party members both a starting point and ending point. Party cadres only opinions, Foundation, Constitution Party rules, series to better add

19、ress outside in shape, “two“ this is State, leading by example, to lead by example to be qualified party members in the process of doing the deep and solid, higher and more stringent. Jobs with new skills. To be a qualified party member, most basic element is always advanced requirements themselves,

20、 using their power to push forward the cause of the party, the people and the nation. Is to the leading cadres of party members, first of all is based on the job, do the people in the heart. There is not a slogan, but aims to better serve the people, targeted efforts to increase the capacity第四章 随机变量

21、的数字特征1. 甲、乙两台自动车床，生产同一种零件，生产 1000 件产品所出的次品数分别用， 表示，经过一段时间的考察，知 ， 的分布律如下： 0 1 2 3 0 1 2p 0.7 0.1 0.1 0.1 p 0.5 0.3 0.2试比较两台车床的优劣。解：因为 E=00.7+10.1+20.1+30.1=0.6;E=00.5+10.3+20.2=0.7。故就平均来说，甲机床要优于乙机床。2. 连续型随机变量 的概率密度为fxkxkaa() (,)010其 它又知 E=0.75，求 k, a 之值 。 解：首先由密度函数性质知1,1,)( adxkdxfa即；又 E=0.75，即有 75.0

22、2,75.0kx即；由上述两式可求得 k=3, a=2。3.已知随机变量 的分布律为 -1 0 2 3p 1/8 1/4 3/8 1/4求 E，E(3 -2)，E 2，E(1- )2 。解：E =(-1)(1/8)+0(1/4)+2(3/8)+3(1/4)=11/8;E2=(-1)2(1/8)+02(1/4)+22(3/8)+32(1/4)=31/8;E(1-)2=(1-(-1)2(1/8)+(1-0)2(1/4)+(1-2)2(3/8)+(1-3)2(1/4)=17/8或者， E(1-)2=E(1-2+2)=1- (E2)+E2=17/8。4. 若 的概率密度为fxex)|1。求(1) E，

23、(2)E 2 。解：(1)de|21中因 e-|x|为偶函数，x 为奇函数，故 xe-|x|为奇函数，且积分区间关于原点对称，该积分又绝对收敛，事实上 1)2(|21)(| 0| dxexf故 E=0。(2) df)(22 !)3(02|exx。5. 轮船横向摇摆的随机振幅 的概率密度为fxAxx() ()2000 求(1)确定系数 A；(2) 遇到大于其振幅均值的概率是多少？解：(1)由密度函数性质知 221,1)( AdAedxf即,leading cadres awareness of right in place, study the party Constitution and pa

24、rty rules, series of speeches can make proper effect. Party cadres to “two“ lead by example, to lead by example we must change our mind, recognizing that “two“ is important. First, learn the Communist Party Constitution Party rules, learning learning series important speech by General Secretary can

25、enhance theory. With the “third revolution“ the rise of rapid changes in our life are feeling, the Communists should adhere to the theory of confidence will continue to learn from the voices of the times, the times, in turn, will have new requirements for leading party cadres. “Two“ is the most basi

26、c meaning of members all mastering the core theory and the most advanced weapons theory, complement the spirit of calcium. Secondly, the Communist Party Constitution Party rules, learning learning series important speech by General Secretary be able to firmly build the ideological foundation. Under

27、the impact of multiple values, the “two“ is to help cultivate independent judgment in numerous miscellaneous multiple concepts, so that the majority consensus of party members, the important magic weapon of the party with the resonance frequency. Finally, the Constitution of the Communist Party, par

28、ty rules, learning learning series important speech can stand crowds, General Secretary position. Now, some grass-roots work in the “the old way didnt work, hard way cannot, the new approach would not“ phenomenon, sometimes due to a mass of party members and cadres not understanding, does not meet.

29、In fact, the mass “convincing“ and “identity“Behind are likely to be party members and leading cadres themselves ignoring beliefs held, resulting in lack of persuasion and sense of identity. “Two“ is in fact guaranteed party cadres work, an important prerequisite for convincing the masses. Bacon sai

30、d it well: “practical men can handle individual matters, but looking at the whole operation globally, but only man can do to knowledge. “Giving up“ two “effective, must first raise awareness of leading cadres of party members, as party members learn real responsibility“ to know “to“ music “,“ good “

31、changes, in parallel with the ground, do not forget to also answer the antenna, draw catches on meteorology, which sit between heaven and Earth which melds together the dreams of practicing Communist. Members cadres should in “two learn a do“ in the based post do contribution in all members in the c

32、arried out “learn Constitution Party rules, and learn series speech, do qualified members“ learning education, this is following party of mass line education practice activities and “three strict three real“ topic education zhihou, deepening party education of and once important practice, is promote

33、d “three strict three real“ topic education from “key minority“ to all members expand, and from concentrated education to regular education extends of important initiatives. Vast numbers of party members and cadres in the course of two, should bebased on their actual, striving to be “learning“ and “

34、done“ markers. Strengthening theoretical study, belief and faith. Theory is an action guide, only theoretical knowledge in place, to unity, action can consciously. Constitution is the fundamental law of the party, party rules are party must follow the General rules. Studying and implementing the par

35、ty Constitution Party rules and a series of important speech, General Secretary, is a guide to persisting and developing socialism with Chinese characteristics, is a basic work of strengthening the partys construction, but also each and every Communist Party Members obligations and solemn responsibi

36、lity. These important content, for each party, must know would believe will do both. WeGeneral Secretary of the party Constitution, a series of remarks with, and hold, grasp the real “learning“ that basis, based on the Constitution speak to issue, in accordance with the series changed the problem. S

37、econd, disciplined in line, to become law-abiding model. Is not no rules. If there is no iron discipline, party members and cadres will become a mess, it will lose its fighting strength and vitality, purity and naturally much less advanced. By “two“ education, party members and cadres to keep the “b

38、ottom line“, not the more “red lines“, consciously practice the “three Suns“ and consciously act according to the Constitution, party rules, remains a political force, to perform party oath, a tree of its own image. Three is the loyal, dare to play and play to party members. Learning is the Foundati

39、on, is the key to development is the goal. “Two“ main objective is to let the majority of the play to the exemplary role of party members and cadres, party Constitution, party rules to examine. To use new criteria to guide our behavior. Through education, the ideal and conviction, keep in mind that

40、membership, learn, learn, learn go play a vanguard and exemplary role, the courage to play as, and always maintain the pioneer, pioneering and enterprising spirit, and constantly improve our own capacity and level of service, according to positions and make contributions. Hearts change, lead more st

41、rict “began in the know, know as Luke Skywalker“, “two“ activities, be qualified party members both a starting point and ending point. Party cadres only opinions, Foundation, Constitution Party rules, series to better address outside in shape, “two“ this is State, leading by example, to lead by exam

42、ple to be qualified party members in the process of doing the deep and solid, higher and more stringent. Jobs with new skills. To be a qualified party member, most basic element is always advanced requirements themselves, using their power to push forward the cause of the party, the people and the n

43、ation. Is to the leading cadres of party members, first of all is based on the job, do the people in the heart. There is not a slogan, but aims to better serve the people, targeted efforts to increase the capacity即 .0,0,)(2xexfx(2)dxeeddfEx 0222)( )(0)(2 ex，4/2222 eedEPxx。6. 一个仪器由两个主要部件组成，其总长度为此二部件长

44、度之和，这两个部件的长度 和 为两个相互独立的随机变量，其分布律如下表： 9 10 11 6 7p 0.3 0.5 0.2 p 0.4 0.6试求 E(+)，E( )。解：因为 E=90.3+100.5+110.2=9.9，E =60.4+70.6=6.6，故 E(+)=E+E=9.9+6.6=16.5；又 和 为两个相互独立的，因此有 E()=EE=9.96.6=65.34。7. 已知( ， )的联合概率密度为fxyxy(,)40101其 它试求 E(2+2)。解：E( 2+2)= 4)(),(1022 xyddxyf。8. 一民航送客车载有 20 位旅客自机场开出，旅客有 10 个车站可以

45、下车，如到达一个车站没有旅客下车就不停车。以 表示停车的次数，求 E (设每位旅客在各个车站下车是等可能的，并设各旅客是否下车是相互独立的)。解：引入随机变量 .,1,0站 有 人 下 车在 第 站 没 有 人 下 车在 第 ii易知， 1021 ，现在求 E 由题设，任一游客在第 i 站不下车的概率为 9/10，因此， 20 位游客都不在第 i 站下车的概率为(9/10) 20，在第 i 站下车的概率为 1-(9/10)20。也就是P i=0=(9/10)20， P i=1=1-(9/10)20( 10,2i)，因此，E i=1-(9/10)20( 10,2)。故 E=E 784.)/9()

46、( 20101021 EE (次)9. 圆的直径用 度量，而 且在a，b 上服从均匀分布，试求圆的周长和圆的面积的数学期望和方差。解：由于 服从a，b 上的均匀分布，因此 的分布密度为其 它,0,)(xxf .12/)(,abDE而圆的周长 L=，圆的面积 A=2/4，故有EL=E()=E= /)(b，leading cadres awareness of right in place, study the party Constitution and party rules, series of speeches can make proper effect. Party cadres to

47、 “two“ lead by example, to lead by example we must change our mind, recognizing that “two“ is important. First, learn the Communist Party Constitution Party rules, learning learning series important speech by General Secretary can enhance theory. With the “third revolution“ the rise of rapid changes in our life are feeling, the Communists should adhere to the theory of confidence will continue to learn from the voices of the times, the times, in turn, will have new requirements for leading party cadres. “Two“ is the most basic meaning of members all mast