Let X and Y be discrete random variables with joint probability mass function (PMF) px (x, y). Answer the following questions a) Show that E[aX +bY +c] =aE[X]+bE[r]+c. b) Assume that X and Y are independent. Show that E[XY]= E[X]E[Y]. c) Assume that X and Y are independent. Show that var(X +Y)= var(X)+ var(Y).

A First Course in Probability (10th Edition)
10th Edition
ISBN:9780134753119
Author:Sheldon Ross
Publisher:Sheldon Ross
Chapter1: Combinatorial Analysis
Section: Chapter Questions
Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...
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Let X and Y be discrete random variables with joint probability mass
function (PMF) px (x, y). Answer the following questions
a) Show that E[ax +bY +c]= aE[X]+ bE[Y]+c.
b) Assume that X and Y are independent. Show that E[XY]= E[X]E[Y].
c) Assume that X and Y are independent. Show that var(X +Y)= var(X)+ var(Y).
Bonus Question
Give a formal definition of a random variable?
Transcribed Image Text:Let X and Y be discrete random variables with joint probability mass function (PMF) px (x, y). Answer the following questions a) Show that E[ax +bY +c]= aE[X]+ bE[Y]+c. b) Assume that X and Y are independent. Show that E[XY]= E[X]E[Y]. c) Assume that X and Y are independent. Show that var(X +Y)= var(X)+ var(Y). Bonus Question Give a formal definition of a random variable?
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