ANSWER:
Suppose that Xi, X2,.... Xn are independent random variables. Assume that E[A]-: μί ald Var(Xi)-σ? where i-| , 2, , n. If ai, aam., an are constants. E{E:-aiX.) and (ii) Var(Σ-lai%). The expression if X,s are not independent.
X1 , X2 , .... , Xn are independent random variables Cov(Xi , Xj) = 0 i,j=1,2,...,n ; ij
(ii)
X1 , X2 , .... , Xn are not independent random variables.
Let ij be the correlation between Xi and Xj i,j=1,2,...,n ; ij
Cov(Xi , Xj) = ijij i,j=1,2,...,n ; ij
explan the answer . Suppose that Xi, X2,.... Xn are independent random variables. Assume that E[A]-:...
explan the answer 1l. Suppose that X1, X2,... Xn are independent random variables. Assume that ElXi] /4 and Var(X )-σ, where i 1, 2, . .., n. If ai , aam. , an are constants. 1,a2, , an are constan (i) Write down expression for (i) E{Σ,i ai Xi) and (ii) Var(Li la(Xi). (i) Rewrite the expression if X,'s are not independent.
Let Xi, X2, , xn be independent Normal(μ, σ*) random variables. Let Yn = n Ση1Xi denote a sequence of random variables (a) Find E(%) and Var(%) for all n in terms of μ and σ2. (b) Find the PDF for Yn for all n c) Find the MGF for Y for all n
Let X1, X2, ....,. Xn, be a set of independent random variables, each distributed as a normal random variable with parameters μί and σ. Let х, ai Use properties of moment generating functions to determine the distribution of Y, meaning: find the type of distribution we get, and its expected value and variance
Xn are independent normal variates with the same variance σ, but with Suppose that Xi, X2, different means, Xi ~N(pbi,ơ2), for i-1.2, n where bi, b,.. k constants. (a) Find expressions for the MLE of μ and σ. You need not show the second derivative conditions (b) Suppose that b,-b2-...-bn. Find a simplified expression for the MLE of μ (c) Suppose that b,-b2-...-bn-1, and , is known. Find the MLE ofơ
Suppose X1, X2,... are independent Geometric (number of trials) random variables where Xi ~ Geometric(p = 1/i^2) a) It is easily shown that Xn converges to a for some constant a. Name it. b) According to the Borel-Cantelli Lemmas, does Xn almost surely converge to a? Suppose Xi, X2, are independent Geometric (number of trials) random variables where x,~ Geometric(pal+) |. a) It is easily shown that Xa for some constant a. Name it. b) According to the Borel-Cantelli Lemmas,...
(a) Suppose that Xi, X2,... are independent and identically distributed random variables each taking the value 1 with probability p and the value-1 with probability 1-p For n 1,2,..., define Yn -X1 + X2+ ...+Xn. Is {Yn) a Markov chain? If so, write down its state space and transition probability matrix. (b) Let Xı, X2, ues on [0,1,2,...) with probabilities pi-P(X5 Yn - min(X1, X2,.. .,Xn). Is {Yn) a Markov chain and transition probability matrix. be independent and identically distributed...
Let X1, X2, , xn are independent random variables where E(X)-? and Var(X) ?2 for all i = 1, 2, , n. Let X-24-xitx2+--+Xy variables. is the average of those random Find E(X) and Var(X).
Let Xi, X2,... , Xn denote independent and identically distributed uniform random variables on the interval 10, 3β) . Obtain the maxium likelihood estimator for B, B. Use this estimator to provide an estimate of Var[X] when r1-1.3, x2- 3.9, r3-2.2
6. Suppose that Xi, X2. Xn are independent random variable thal are uniformly distributed in the unit interval (0, Let Y maxXi, X2Xnbe their maximum value. Determine the disiribution function and the density of Y and thence evaluale E(Y) and Var(Y
Problem 7. Let Xi, X2,..., Xn be i.i.d. (independent and identically distributed) random variables with unknown mean μ and variance σ2. In order to estimate μ and σ from the data we consider the follwing estimates n 1 Show that both these estimates are unbiased. That is, show that E(A)--μ and