Let {Xn} be a sequence of iid random variables
Let {Xn} be a sequence of iid random variables 1. (20 points) Let {Xn} be a...
- Let {Xn} denote a sequence of iid random variables such that P(Xi = 1) = P(X1 = -1) = 1/2. Let Sn = X1 + X2 + ... + xn. (a) Find ES, and var(Sn); (b) Show that Sn is a martingale.
3. Let X1, . . . , Xn be iid random variables with mean μ and variance σ2. Let X denote the sample mean and V-Σ,(X,-X)2 a) Derive the expected values of X and V b) Further suppose that Xi,...,Xn are normally distributed. Let Anxn - ((a) be an orthogonal matrix whose first row is (mVm Y = (y, . . . ,%), and X = (Xi, , Xn), are (column) vectors. (It is not necessary to know aij for...
7. Let Xn Xi++X2, where the Xi's are iid standard normal random variables (a) Show that Sn is a chi-square random variable with n de- grees of freedom. Hint: Show that X is chi-square with one degree of freedom, and then use Problem 6. (b) Find the pdf of (c) Show that T2 is a Rayleigh random variable. (d) Find the pdf for Ts. The random variable Ts is used to model the speed of molecules in a gas. It...
3. (a) (5 points) Let Xi,... be a sequence of independent identically distributed random variables e of tnduqendent idente onm the interval (o, 1] and let Compute the (almost surely) limit of Yn (b) (5 points) Let X1, X2,... be independent randon variables such that Xn is a discrete random variable uniform on the set {1, 2, . . . , n + 1]. Let Yn = min(X1,X2, . . . , Xn} be the smallest value among Xj,Xn. Show...
Let X1, X2, ..., Xn be iid random variables with a "Rayleigh” density having the following pdf: 22 -12 10 f(x) = e x > 0 > 0 0 пе a) (3 points) Find a sufficient estimator for 0 using the Factorization Theorem. b) (3 points) Find a method of moments estimator for 0. Small help: E(X1) = V c) (7 points) What is the MLE of 02 + 0 – 10 ? d) (7 points) For a fact, 21–1...
if Xn are iid continuous random variables in n according to the PDF of fx , and Z is a positive discrete random variable according to Y= sum of Xn. Find the MGF of Y in terms of Z and X 工、エ.D ARE CONTINUOUS RANDOM VARIABLES ACCORDIN IN TO 7IS OISTRI BUTION AND VAR TABLE DISCRETE A RANOOM PO SITLVE LET Y=X TERMS OF YIN MGF OF ERPRESS AND LJ
3 Minimum of IID exponentials Let Z1, ..., Zn be IID exponential random variables with mean 8. That is, each Z has a PDF given by: f(3) = exp(-z/B], where 2 and 3 are positive. x f(x) dx Derive the probability density function for min(Z......) (.e., the minimum of random variables 21,..., 2n). You should find that the probability density function for min(Z1,..., Zn) is that of an expo nential random variable. What is the mean of min(21,..., 2..)?
Let X1, X2, . . . , Xn be a sequence of independent random variables, all having a common density function fX . Let A = Sn/n be their average. Find fA if (a) fX (x) = (1/ √ 2π)e −x 2/2 (normal density). (b) fX (x) = e −x (exponential density). Hint: Write fA(x) in terms of fSn (x).
1. Let X1, X2, , Xn be independent Normal μ, σ2) random variables. Let y,-n Σ_lx, denote a sequence of random variables (a) Find E(y,) and Var(y,) for all n in terms of μ and σ2. (b) Find the PDF for Yn for alln. (c) Find the MGF for Yn for all n.
1. The random variables Xi, X2,... are independent and identically distributed (iid), . .. are independent and identica each with pdf f given in Assignment 4, Question 1. Let s, X1 + . .. + Xn. Using the Central Limit Theorem and the graph of the standard normal distribution in Figure 1, approximate the probability P(S100 > 600). Express your answer in the format x.x - 10*. Verify your answer by simulating 10,000 outcomes of S1o0 and counting how many...