
sucCesses isk. 6142 Let S consist of the 10 decimal digits. Suppose that a number X...
(a) Consider four independent rolls of a 6-sided die. Let X be the number of l's and let y be the number of 2's obtained. What is the joint PMF of X and Y? (b) Let X1, X2, X3 be independent random variables, uniformly distributed on [0,1]. Let Y be the median of X1, X2, X3 (that is the middle of the three values). Find the conditional CDF of X1, given that Y = 0.5. Under this conditional distribution, is...
3. Let f(x,y) = xy-1 be the joint pmf/ pdf of two random variables X (discrete) and Y (continuous), for x = 1, 2, 3, 4 and 0 <y < 2. (a) Determine the marginal pmf of X. (b) Determine the marginal pdf of Y. (c) Compute P(X<2 and Y < 1). (d) Explain why X and Y are dependent without computing Cou(X,Y).
Please answer the question clearly
10. If two cards are randomly drawn (without replacement) from an ordinary deck of 52 playing cards, let Z be the number of Kings obtained from the first draw and let W be the total number of Kings obtained from both draws. The table below provides values for f(z, w), the joint distribution (PMF) of Z and W. 188 221 16 221 16 221 221 (a) Find the marginal distribution (PMF) of Z (b) Find...
Proposition 6.10 Independent Discrete Random Variables: Bivariate Case Let X andY be two discrete random variables defined on the same sample space. Then X and Y are independent if and only if pxy(x,y) = px(x)py(y), for all x , y ER. (6.19) In words, two discrete random variables are independent if and only if their joint equals the product of their marginal PMFs. Proposition 6.11 Independence and Conditional Distributions Discrete random variables X and Y are independent if and only...
4. Let S be the shadowed region as in the figure below: (c) Calculate E(Y | X = x). Does this make sense to you intu- itively? -3 -1 1 3 Suppose that (X,Y) have a uniform distribution over S, i.e., their joint PDF is given by fx,8(x,y) = a (x,y) ES (a) Find the marginal PDF fx(x) of X. (d) Calculate E(Y). (b) Determine the conditional PDF fyıx(y|x).
2. Let X denote the number of times (1, 2, or 3 times) a certain machine malfunctions on any given day. Let Y denote the number of times (1, 2, or 3 times) a technician is called on an emergency call. The joint probability distribution fxy(x, y) is given by 1 0.05 0.05 0 0.05 0.1 0.2 0.1 0.35 0.1 (a) Evaluate the marginal pdf and the mean of X (b) Evaluate the marginal pdf and the mean of Y....
5. Let X have a uniform distribution on the interval (0,1). Given X = x, let Y have a uniform distribution on (0, 2). (a) The conditional pdf of Y, given that X = x, is fyıx(ylx) = 1 for 0 < y < x, since Y|X ~U(0, X). Show that the mean of this (conditional) distribution is E(Y|X) = , and hence, show that Ex{E(Y|X)} = i. (Hint: what is the mean of ?) (b) Noting that fr\x(y|x) =...
(f) Find the conditional pmf of X given Z. Identify this
conditional distribution as a distribution known in class, and
give
the explicit parameters for the known distribution.
(g) Find the conditional expectation of X given Z.
2. (Lec 13 &15 & 16 pairs of discrete R.V., conditional pmf and conditional moments, 17 pts) We are studying the flow of packets at a switch, which receives packets from two transmission paths, during a given period of time. Let X and...
Let X denote the number of
times (1, 2, or 3 times) a certain machine malfunctions on any
given day.
2. Let X denote the number of times (1, 2, or 3 times) a certain machine malfunctions on any given day. Let Y denote the number of times (1, 2, or 3 times) a technician is called on an emergency call. The joint probability distribution fxy(x, y) is given by 1 2 y 0.05 1 0.05 0.1 2 0.05 0.1...
10. Let X and Y have a discrete joint distribution with if (x,y) = (-1,1) P(X = 2, Y = y) = { = ; if x=y=0 = 0, elsewhere Find (a) the conditional distribution of Y given X = -1. (b) show that X and Y are uncorrelated but not independent. (C) Find the marginal distributions of X and Y.