Exercise I. Let X,Y~ N(0, 1) be jointly Gaussian random variables and let t€ R. The goal of this exercise is to prove the following identity, using three different ways: E[Xe] =tE[XY]E[e¹Y]. (*) 1. a. Prove that E[Xe¹x] = tE[e¹x]. b. Set p = E[XY]. Show that (X,Y) law (X, pX+√√1 - p²Z), where Z~ N(0, 1) is independent from X. Deduce that (*) holds true. 2. We recall from the lecture notes that ety = ef [²0 ef #H(y) for all y € R. By applying this identity to y = Y, give a second proof of (*). 3. For s € R, compute E[e*X+tY] using the known expression for the Laplace transform of a Gaussian random variable, and then give a third proof of (*) by differentiating with respect to s.
Exercise I. Let X,Y~ N(0, 1) be jointly Gaussian random variables and let t€ R. The goal of this exercise is to prove the following identity, using three different ways: E[Xe] =tE[XY]E[e¹Y]. (*) 1. a. Prove that E[Xe¹x] = tE[e¹x]. b. Set p = E[XY]. Show that (X,Y) law (X, pX+√√1 - p²Z), where Z~ N(0, 1) is independent from X. Deduce that (*) holds true. 2. We recall from the lecture notes that ety = ef [²0 ef #H(y) for all y € R. By applying this identity to y = Y, give a second proof of (*). 3. For s € R, compute E[e*X+tY] using the known expression for the Laplace transform of a Gaussian random variable, and then give a third proof of (*) by differentiating with respect to s.
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
Related questions
Question
![Exercise I. Let X, Y ~ N(0, 1) be jointly Gaussian random variables and let t€ R. The
goal of this exercise is to prove the following identity, using three different ways:
E[Xe] =tE[XY] E[e¹]. (*)
1. a. Prove that E[XeX] = tE[e¹X].
b. Set p = E[XY]. Show that (X, Y) Law (X, pX+√√1 - p²Z), where Z~ N(0, 1)
is independent from X. Deduce that (*) holds true.
2. We recall from the lecture notes that ety=eH(y) for all y € R. By
applying this identity to y = Y, give a second proof of (*).
3. For s R, compute E[esX+tY] using the known expression for the Laplace transform
of a Gaussian random variable, and then give a third proof of (*) by differentiating
with respect to s.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F7bf11458-9a82-4c45-a895-ac6b301730be%2F7680adb4-6735-4b28-866f-471d2db3f93d%2Fumizogk_processed.png&w=3840&q=75)
Transcribed Image Text:Exercise I. Let X, Y ~ N(0, 1) be jointly Gaussian random variables and let t€ R. The
goal of this exercise is to prove the following identity, using three different ways:
E[Xe] =tE[XY] E[e¹]. (*)
1. a. Prove that E[XeX] = tE[e¹X].
b. Set p = E[XY]. Show that (X, Y) Law (X, pX+√√1 - p²Z), where Z~ N(0, 1)
is independent from X. Deduce that (*) holds true.
2. We recall from the lecture notes that ety=eH(y) for all y € R. By
applying this identity to y = Y, give a second proof of (*).
3. For s R, compute E[esX+tY] using the known expression for the Laplace transform
of a Gaussian random variable, and then give a third proof of (*) by differentiating
with respect to s.
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps

Recommended textbooks for you

MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc

Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning

MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc

Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning

Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON

The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman

Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman