Exercise 13. Let X₁,..., Xn~ N(a,02) i.i.d. and Y₁,..., Yn~ N(y, o2) i.i.d. with known o². We assume that for each i the random variables X, and Y; are correlated, with Corr(X₁, Yi) = 1/2. Define Di Xi - Yi for all i E {1,...,n}. Finally, let X, Y and D be the averages of the Xi, Yi and Di, respectively. = a) Show that Cov(X₁, Yi) = 0²/2. b) Determine E(D₁) and Var(D₂). c) Consider the test for Ho: x=y which uses the test statistic Z = √nº. O and which rejects Ho, if and only if |Z| > 1.96. Show that P(type I error) = 5%. d) In two or three sentences, discuss the differences between the test from part (c) on the one hand, and the non-paired test for comparing the means of two populations on the other

Algebra & Trigonometry with Analytic Geometry
13th Edition
ISBN:9781133382119
Author:Swokowski
Publisher:Swokowski
Chapter10: Sequences, Series, And Probability
Section10.8: Probability
Problem 32E
icon
Related questions
Question
Exercise 13. Let X₁,..., Xn~ N(x, 0²) i.i.d. and Y₁,..., Yn ~ N(µy, 02) i.i.d. with known o².
We assume that for each i the random variables X; and Y; are correlated, with Corr(Xį, Y₁) = 1/2.
Define D₁ = X₁ - Yį for all i = {1,...,n}. Finally, let X, Y and D be the averages of the Xi, Yi
and Di, respectively.
a) Show that Cov(X₁, Yi) = 0²/2.
b) Determine E(D₁) and Var(D₁).
c) Consider the test for Ho: x = µy which uses the test statistic
Z = √√nD
σ
and which rejects Ho, if and only if |Z| > 1.96. Show that P(type I error) = 5%.
d) In two or three sentences, discuss the differences between the test from part (c) on the one
hand, and the non-paired test for comparing the means of two populations on the other
hand.
Transcribed Image Text:Exercise 13. Let X₁,..., Xn~ N(x, 0²) i.i.d. and Y₁,..., Yn ~ N(µy, 02) i.i.d. with known o². We assume that for each i the random variables X; and Y; are correlated, with Corr(Xį, Y₁) = 1/2. Define D₁ = X₁ - Yį for all i = {1,...,n}. Finally, let X, Y and D be the averages of the Xi, Yi and Di, respectively. a) Show that Cov(X₁, Yi) = 0²/2. b) Determine E(D₁) and Var(D₁). c) Consider the test for Ho: x = µy which uses the test statistic Z = √√nD σ and which rejects Ho, if and only if |Z| > 1.96. Show that P(type I error) = 5%. d) In two or three sentences, discuss the differences between the test from part (c) on the one hand, and the non-paired test for comparing the means of two populations on the other hand.
Expert Solution
steps

Step by step

Solved in 8 steps with 14 images

Blurred answer
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Algebra & Trigonometry with Analytic Geometry
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage
Glencoe Algebra 1, Student Edition, 9780079039897…
Glencoe Algebra 1, Student Edition, 9780079039897…
Algebra
ISBN:
9780079039897
Author:
Carter
Publisher:
McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Big Ideas Math A Bridge To Success Algebra 1: Stu…
Algebra
ISBN:
9781680331141
Author:
HOUGHTON MIFFLIN HARCOURT
Publisher:
Houghton Mifflin Harcourt