Let Y, represent the ith normal population with unknown mean 4, and unknown variance of for i=1,2. Consider independent random samples, Ya, Y2Yin, of size n,, from the ith population with sample mean Y, and sample variance S?=1 Σj-1(Y₁-₁². (a) What is the distribution of Y? State all the relevant parameters of the distribution. (b) Find a level a test (that is, the rejection region) for testing Ho = o versus Ha Pio when of is unknown and n, is small. (e) In the context of the test in part (b), state the Type I error and give a probability statement for the level of significance, a.

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...
icon
Related questions
Question
Let Y, represent the ith normal population with unknown mean 4, and unknown variance
of for i=1,2. Consider independent random samples, Ya, Y₁2, Yin, of size n,, from
the ith population with sample mean Y, and sample variance S?=1 Σ₁-1 (₁-₁)².
(a) What is the distribution of Y? State all the relevant parameters of the distribution.
(b) Find a level a test (that is, the rejection region) for testing Ho: #₁ = μio versus
Ha Hi Ho when of is unknown and n, is small.
:
(c) In the context of the test in part (b), state the Type I error and give a probability
statement for the level of significance, a.
Transcribed Image Text:Let Y, represent the ith normal population with unknown mean 4, and unknown variance of for i=1,2. Consider independent random samples, Ya, Y₁2, Yin, of size n,, from the ith population with sample mean Y, and sample variance S?=1 Σ₁-1 (₁-₁)². (a) What is the distribution of Y? State all the relevant parameters of the distribution. (b) Find a level a test (that is, the rejection region) for testing Ho: #₁ = μio versus Ha Hi Ho when of is unknown and n, is small. : (c) In the context of the test in part (b), state the Type I error and give a probability statement for the level of significance, a.
Expert Solution
Step 1: Write the distribution of Yi bar and state its all the relevant parameters

Consider the independent random variables, Y subscript i 1 end subscript comma space Y subscript i 2 end subscript comma space. space. space. comma space Y subscript i n subscript i end subscript of size n subscript i from the ith population with sample mean Y with bar on top subscript i and sample variance S subscript i superscript 2 equals fraction numerator 1 over denominator n subscript i minus 1 end fraction sum from j equals 1 to n subscript i of open parentheses Y subscript i j end subscript minus Y with bar on top subscript i close parentheses squared.

(a) 

The distribution of the sample mean Y with bar on top subscript i will have the following parameters:

  • Mean (E open parentheses Y with bar on top subscript i close parentheses): The expected value of will be equal to the population mean, which is .
  • Variance (Var open parentheses Y with bar on top subscript i close parentheses): The variance of  will be equal to the population variance divided by the sample size, i.e., Y with bar on top subscript ifraction numerator sigma subscript i superscript 2 over denominator n subscript i end fraction.
  • Standard deviation (S D open parentheses Y with bar on top subscript i close parentheses): The standard deviation of Y with bar on top subscript i will be the square root of its variance, i.e.,

The distribution of Y with bar on top subscript i is normal distribution since the samples are taken from a normal distribution.

table row cell E open square brackets Y with bar on top subscript i close square brackets end cell equals cell E open square brackets fraction numerator sum from j equals 1 to n subscript i of Y subscript i j end subscript over denominator n subscript i end fraction close square brackets end cell row blank equals cell 1 over n subscript i cross times E open square brackets sum from j equals 1 to n subscript i of Y subscript i j end subscript close square brackets end cell row blank equals cell 1 over n subscript i cross times sum from j equals 1 to n subscript i of E open square brackets Y subscript i j end subscript close square brackets end cell row blank equals cell 1 over n subscript i cross times sum from j equals 1 to n subscript i of mu subscript i end cell row blank equals cell 1 over n subscript i cross times n subscript i mu subscript i end cell row blank equals cell mu subscript i end cell end table

table row cell V a r open square brackets Y with bar on top subscript i close square brackets end cell equals cell V a r open square brackets fraction numerator sum from j equals 1 to n subscript i of Y subscript i j end subscript over denominator n subscript i end fraction close square brackets end cell row blank equals cell 1 over open parentheses n subscript i close parentheses squared cross times V a r open square brackets sum from j equals 1 to n subscript i of Y subscript i j end subscript close square brackets end cell row blank equals cell 1 over open parentheses n subscript i close parentheses squared cross times sum from j equals 1 to n subscript i of V a r open square brackets Y subscript i j end subscript close square brackets end cell row blank equals cell 1 over open parentheses n subscript i close parentheses squared cross times sum from j equals 1 to n subscript i of sigma subscript i superscript 2 end cell row blank equals cell 1 over open parentheses n subscript i close parentheses squared cross times n subscript i sigma subscript i superscript 2 end cell row blank equals cell fraction numerator sigma subscript i superscript 2 over denominator n subscript i end fraction end cell end table

The relevant parameters of the distribution are sample mean is mu subscript i and sample variance is fraction numerator sigma subscript i superscript 2 over denominator n subscript i end fraction.

steps

Step by step

Solved in 3 steps with 43 images

Blurred answer
Similar questions
Recommended textbooks for you
A First Course in Probability (10th Edition)
A First Course in Probability (10th Edition)
Probability
ISBN:
9780134753119
Author:
Sheldon Ross
Publisher:
PEARSON
A First Course in Probability
A First Course in Probability
Probability
ISBN:
9780321794772
Author:
Sheldon Ross
Publisher:
PEARSON