/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q.23 Show that Z聽is a standard norma... [FREE SOLUTION] | 魅影直播

魅影直播

Show that Zis a standard normal random variable and if Yis defined by Y=a+bZ+cZ2, then

(Y,Z)=bb2+2c2

Short Answer

Expert verified

We prove thatY=a+bZ+cZ2

Step by step solution

01

Given information

Given in the question that,Y=a+bZ+cZ2.

02

Explanation

Let Zis a standard normal random variable N(0,1), and Y=a+bZ+cZ2

Now, it can be shown(Y,Z)

(Y,Z)=Cov(Y,Z)Var(Y)Var(Z)

=bVar(Z)+cEZ3-cEZ2E(Z)

E(Z)=0,Var(Z)=1, because Zare standard normal random variable.

EZ3=0order moments are always zero,

Cov(Y,Z)=bVar(Z)=b

Var(Y)=b2Var(Z)+c2VarZ2

=b2+c2EZ4-c2EZ22

=b2+3c2-1c2

=b2+2c2

(Y,Z)=bb2+2c21=bb2+2c2

Hence, we obtain:

(Y,Z)=bb2+2c2

03

Final answer

We prove thatY=a+bZ+cZ2

and

(Y,Z)=bb2+2c2

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 魅影直播!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Let Z be a standard normal random variable,and, for a 铿亁ed x, set

X={ZifZ>x0otherwise

Show thatE[X]=12ex2/2.

The number of accidents that a person has in a given year is a Poisson random variable with mean 蹋 However, suppose that the value of changes from person to person, being equal to 2for 60percent of the population and 3for the other 40percent. If a person is chosen at random, what is the probability that he will have

(a) 0accidents and,

(b) Exactly 3accidents in a certain year? What is the conditional probability that he will have3 accidents in a given year, given that he had no accidents the preceding year?

Show that Xis stochastically larger than Yif and only ifE[f(X)]E[f(Y)]

for all increasing functions f..

Hint: Show that XstY, then E[f(X)]E[f(Y)]by showing that f(X)stf(Y)and then using Theoretical Exercise 7.7. To show that if E[f(X)]E[f(Y)]for all increasing functions f, then P{X>t}P{Y>t}, define an appropriate increasing function f.

The joint density of X and Y is given by

f(x,y)=12e-ye-(x-y)2/20<y<,

-<x<

(a) Compute the joint moment generating function of X and Y.

(b) Compute the individual moment generating functions.

Urn 1contains 5white and 6black balls, while urn 2contains 8white and 10black balls. Two balls are randomly selected from urn 1and are put into urn 2. If 3balls are then randomly selected from urn 2, compute the expected number of white balls in the trio.

Hint: LetXi = 1if the i th white ball initially in urn 1is one of the three selected, and let Xi = 0otherwise. Similarly, let Yi = 1if the i the white ball from urn 2is one of the three selected, and let Yi = 0otherwise. The number of white balls in the trio can now be written as15Xi+18Yi

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.