Q1:Suppose X and Y are independent events with marginal probabilities of 0.47 and 0.87 respectively.What is the probability that either event occurs?( 3 decimal places ) Q2:A Melbourne real estate agent lists two houses for lease in the same street

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/06 17:55:15

Q1:Suppose X and Y are independent events with marginal probabilities of 0.47 and 0.87 respectively.What is the probability that either event occurs?( 3 decimal places )
Q2:A Melbourne real estate agent lists two houses for lease in the same street,one built of brick and the other of timber.The agent estimates that the probability of being leased within one week is 0.69 for the brick and 0.68 for the timber house,and the probability of both being leased within one week is 0.52.If the timber house is leased within one week,what is the probability that the brick house is also leased within one week?Give your answer correct to three decimal places.

Q1:由题意,X、Y是相互独立的随机变量,并且各自发生的概率(即题目中说的边缘分布)分别为Px=0.47,Py=0.87.
题目要问的是“两者至少有一个发生的概率”,即事件A并(即符号U,百度不能打数学符号)B
由概率的加法公式(概率的一个性质)
P(A并B)=P(A)+P(B)-P(A交B)
由于A、B是相互独立的随机变量,故P(A交B)=P(A)P(B)=0.47*0.87=0.4089
代入前式得
P(A并B)=P(A)+P(B)-P(A交B)=0.47+0.87-0.4089=0.9311约等于0.931 完毕
-----------------------------------
Q2:一个墨尔本房地产代理商列出了同一条街道上的两幢待出租的房子,一个是砖房,另一个是木房.代理商估计砖房在一个星期内能租出去的概率是0.69,而木房在一个星期内租出去的概率是0.68,而砖房和木房在一周内同时租出去的概率是0.52.问:如果木房在一个星期内租出,那么砖房在一个星期内也租出去的概率是多少?给出你的答案并保留结果至小数点后3位.
设A表示事件“砖房在一个星期内能租出去”,则P(A)=0.69,设B表示事件“木房在一个星期内租出去”,则P(B)=0.68.那么A交B就表示“砖房和木房在一个星期内同时租出”,即P(A交B)=P(AB)=0.52.下面看问题要我们求什么.
“如果木房在一个星期内租出,那么砖房在一个星期内也租出去的概率是多少”,显然,这是条件概率问题.问题所求即为P(A|B).至此,对题目已经完全明白,并且建立合适的模型,接下来开始计算.
由条件概率公式
P(A|B)=P(AB)/P(B)
式子右边的分子和分母题目恰好都告诉我们了,代入得
P(A|B)=P(AB)/P(B)=0.52/0.68约等于0.765
(这里题目有了多余的条件P(A)=0.69)
总结:主要是要把题目所讲的事件用数学语言描述,然后根据问题找出相应的数学模型(或者叫数学公式)去解决它.

Q1:Suppose X and Y are independent events with marginal probabilities of 0.47 and 0.87 respectively.What is the probability that either event occurs?( 3 decimal places ) Q2:A Melbourne real estate agent lists two houses for lease in the same street 求教一道统计学数学题.Suppose X and Y are random variables such that the atandard deviation of X is 2 and the standard deviation of Y is 5.Consider a random variable Z defined as Z=3X-2Y+5.问 a:Assume that X and Y are independtly distribute 关于 是否存在这样的函数( 个人觉得是 常微分方程问题)Is there such a function?suppose g is a function satisfying the following two preperties:(a).g(x)=xg(1/x),for all real numbers x( x is not zero),and(b).g(x)+g(y)=1+g(x+y) f 一道编码理论里面的题目~Let x,y be codewords in a self-orthogonal binary code.Suppose the weights of x and y are both divisible by 4.Show that the weight of x + y is also a multiple of 4. 微积分和微分方程问题Suppose f(x) is a continuous function with positive values and f(0)=1.If for any x>0,the length of the curve y=f(x) over the interval [0,x] is always equal to the area of the region below this curve and above the x-axis, Suppose X has a geometric distribution with parameter p.Show that if n and k are positiveintegers,thenP(X = n + kjX > n) = P(X = k): Suppose I give you a ring and let you know.这句话里面为什么suppose在句首,怎么翻译 AP物理suppose we are asked to find volume of a solid whose base is the circlesuppose we are asked to find volume of a solid whose base is the circle x^2+y^2=4,and where cross-sections perpendicular to the x-axis are all square whose sides lie on th 线性代数关于矩阵的问题、Suppose that AX = B is the matrix representation of a system of linearequations.(a) Suppose that Y is a solution of this system,and that Z1 and Z2 are solutions ofthe associated homogeneous system.Show that Y h 线性代数关于矩阵的问题,Suppose that AX = B is the matrix representation of a system of linearequations.(a) Suppose that Y is a solution of this system,and that Z1 and Z2 are solutions ofthe associated homogeneous system.Show that Y ⣵ 已知命题P1:函数y=2^x-2^-x在R上是增函数,p2:函数y=2^+2^-x在R上是减函数,则在命题q1:p1Vp2,p1^p2,q3:(-p1)Vp3和q4:p1^(-p2)中,真命题是A:q1,q3 B:q2,q3 C:q1,q4 D:q2,q4 关于一个很简单的经济学计算的问题GRAPHICAL ANALYSIS OF CONSUMER CHOICE A.Budget Sets.Consider a consumer who possesses a given amount of money,I.Suppose that he allocates these funds on for the consumption of two goods,X and Y.The budg MBA题Suppose the cross-price elasticity of demand between goods X and Y is 4.How much would the price of good Y have to change in order to change the consumption of good X by 20 percent? Suppose you are sick.Write a note to your head teacher and ask for a leave probailty question (ANOTHER)3.Suppose that a discrete random variable X assumes values from the set SX = {0,1,2,…,8}.Suppose that the pmf of X has the form,px(k) = a*k for k=0,1,2,...,8and zero otherwise.(a) Find the value of a .(b) Find the probab 线性代数相关证明 Suppose that,for a given matrix A,there is a nonzero vector x such that Ax=0.Show that there is also a nonzero vector y such that A*y=0 suppose that f(x)=3x+5 and g(x)=-2x+15.solve |f(suppose that f(x)=3x+5 and g(x)=-2x+15.solve |f(x)|>2 用移向做 3q1.3分之y=y-42.2x:3=6:5