This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Practice questions for Quiz 6 to be given on October 27 ______1. Suppose that X has mean μ =5 and σ =10 and Y= 6 4X. The standard deviation of Y equals_____ _____2. Suppose that X 1 , X 2 and X 3 have mean μ =5 and σ 2 = 4 and Cov(X j , X k ) =0 for j ≠ k . Then the variance of Y= X 1 – X 2 + 2X 3 equals_______ 34. Suppose we take a random sample of n=4 values of X. We let X 1 denote the first value in the sample, X 2 denote the second value, X 3 denote the 3 rd value and X 4 denote the 4 th value. Given (1) μ 1 = μ 2 = μ 3 = μ 4 = μ x = 2 and (2) σ 1 = σ 2 = σ 3 = σ 4 =σ 2 x =9. Let 4 4 1 ∑ = = i i X X . _______ 3. Regardless of the value of N, the mean value of X equals____ ________ 4. If N>> 4 then Cov(X j , X k ) = 0 for all j ≠k and the X j are independent, so Var( X ) = ____ 1 SOLUTIONS TO QUIZ 4A ___ 40 ___ 1. Suppose that X has mean μ =5 and σ =10 and Y= 6 4X. The standard deviation of Y equals_____ Y= 64X. If Y=aX + b then σ 2 Y = a 2 σ...
View
Full
Document
This homework help was uploaded on 01/31/2008 for the course AMS 310.01 taught by Professor Mendell during the Fall '03 term at SUNY Stony Brook.
 Fall '03
 Mendell

Click to edit the document details