EXERCISE 1 A pdf or pmf is called an exponential family if it can be expressed...
1. What values for a and β produce a pdf which is uniform on [0,1]? 2, what relationship between a and β produces a symmetric pdf? 3. What relationship between α and β produces a pdf which is skewed to the right? 4.a. What values for α and β produce a triangular pdf? 4.b. How should I choose α and β if I want a big spike at x-5, and 0 everywhere else? 1. What values for a and β...
3. Consider a continuous random variable X with pdf given by 0, otherwise This is called the exponential distribution with parameter X. (a) Sketch the pdf and show that this is a true pdf by verifying that it integrates to 1 (b) Find P(X < 1) for λ (c) Find P(X > 1.7) for λ : 1
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).
Exercise 7. Let X and Y be A. independent exponential random variables with a common parameter (1) Find the transform associated with aX +Y, where a is a constant. (2) Use the result of part (1) to find the PDF of aX +Y, for the case where a is positive and different than1 (3) Use the result of part (1) to find the PDF of X-Y. Justify your answers. Exercise 7. Let X and Y be A. independent exponential random...
Consider the simplified Bayesian model for normal data The joint posterior pdf is ful, σ21 x)a(σ2,-/2-1 expl_jy.tx, _aPI The marginal posterior pdfs of μ and σ 2 can be obtained by integrating out the other variable (8.30) y@1 x) α (σ2)-m;,-1/2 expl-- Σ.-tri-x)2 (8.31) d. Let q1 and q2 be they/2 and 1-y/2 quantiles of (8.31). Show that the 1-γ credible interval (gi,q2) is identical to the classic confidence interval (5.19) (with ar replaced by y). Hence, a (1-α) stochastic...
1. Assume n i.id. draws from Y ~ Weibull(9,%), with pdf: where γ-γ0 is a given value and the only unknown parameter is θ. (a) Show that the distribution of Y (for given γ-γ°) admits MyBU estimation of a particular function ψ(0) by showing that the joint pdf. f(y|θ, γ0), belongs to the exponential family with: TL K (e) TL (b) It can be shown that the median of Y is median(Yja, γο-θ(log 2) 1/γο, Take as a given (i.e....
Hi, I am asked to write a Normal(μ,1) density in exponential family form.and to provide the next values: 1.Provide the expression for y, the sufficient statistic vector 2.Provide the expression for α, the coefficient vector. 3. Provide the expression for normalizing function ψ(α) 4. Provide the expression for f0(x)
Assume that you have random variable X with pdf or pmf f(x; θ1, . . . , θk). Let X1, . . . , Xn be a random sample from X. Then Mj = (1/n)Xn i=1 (Xi)j is known as the j-th sample moment of the sample. The moment estimators of θ1, . . . , θk, denoted by ˜θ1, . . . , ˜θk, are the values of θ1, . . . , θk which solve the k equations...
he second form for one-parameter exponential family distributions, introduced during lecture 09.1, was Jy (y | θ) = b(y)ec(0)t(y)-d(0) Let η = c(0). If c is an invertible function, we can rewrite (1) as where η is called the natural, or canonical, parameter and K(n) = d(C-1(n)). Expression (2) is referred to as the canonical representation of the exponential family distribution (a) Function κ(η) is called the log-normalizer: it ensures that the distribution fy(y n) integrates to one. Show that,...
1. Consider a GLM (generalised linear model) for a Poisson random sample Y1,. .. , Y, with \Vi each Yi having a pdf or pmf f(y; A;) = i= 1, . .. ,n. Yi = 0, 1,2, -..; ^; > 0; Y;! Note that the pdf from an exponential family has the following general form b(0) + c(y, a(o) y0 exp f(y; 0, 6) = Suppose the linear predictor of the GLM is n = a+Bxi, with (a,B) being the...