A variable of two populations has a mean of 55 and a standard deviation of 24 for one of the populations and a mean of 55 and a standard deviation of 40 for the other population. Complete parts (a) through (C). a. For independent samples of size 16 and 25, respectively, find the mean and standard deviation of x1 - x2. (Assume that the sampling is done with replacement or that the population is large enough.) The mean of x, - x2 is O. (Type an integer or a decimal. Do not round.) b. Must the variable under consideration be normally distributed on each of the two populations for you to answer part (a)? Explain your answer. c. Can you conclude that the variable x, - x2 is normally distributed? Explain your answer.

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
icon
Concept explainers
Topic Video
Question
100%
### Problem Statement

A variable of two populations has a mean of 55 and a standard deviation of 24 for one of the populations and a mean of 55 and a standard deviation of 40 for the other population. Complete parts (a) through (c).

**a.** For independent samples of size 16 and 25, respectively, find the mean and standard deviation of \( \overline{x}_1 - \overline{x}_2 \). (Assume that the sampling is done with replacement or that the population is large enough.)

The mean of \( \overline{x}_1 - \overline{x}_2 \) is [ ].
(Type an integer or a decimal. Do not round.)

**b.** Must the variable under consideration be normally distributed on each of the two populations for you to answer part (a)? Explain your answer.

**c.** Can you conclude that the variable \( \overline{x}_1 - \overline{x}_2 \) is normally distributed? Explain your answer.

### Explanation

#### Part (a): Finding the Mean and Standard Deviation

To find the mean and standard deviation of \( \overline{x}_1 - \overline{x}_2 \), we're given:

- Mean and standard deviation for Population 1: μ1 = 55, σ1 = 24
- Mean and standard deviation for Population 2: μ2 = 55, σ2 = 40
- Sample sizes: n1 = 16, n2 = 25

To find the mean \( \mu \) of the difference in sample means \( \overline{x}_1 - \overline{x}_2 \):

\[ \mu_{\overline{x}_1 - \overline{x}_2} = \mu_1 - \mu_2 \]

To find the standard deviation \( \sigma \) of the difference in sample means \( \overline{x}_1 - \overline{x}_2 \):

\[ \sigma_{\overline{x}_1 - \overline{x}_2} = \sqrt{\left(\frac{\sigma_1^2}{n1}\right) + \left(\frac{\sigma_2^2}{n2}\right)} \]

#### Part (b): Normal Distribution in Each Population

Discuss whether the variable needs to be normally distributed in each of the two populations to determine whether the sample means \( \overline{x}_1 \
Transcribed Image Text:### Problem Statement A variable of two populations has a mean of 55 and a standard deviation of 24 for one of the populations and a mean of 55 and a standard deviation of 40 for the other population. Complete parts (a) through (c). **a.** For independent samples of size 16 and 25, respectively, find the mean and standard deviation of \( \overline{x}_1 - \overline{x}_2 \). (Assume that the sampling is done with replacement or that the population is large enough.) The mean of \( \overline{x}_1 - \overline{x}_2 \) is [ ]. (Type an integer or a decimal. Do not round.) **b.** Must the variable under consideration be normally distributed on each of the two populations for you to answer part (a)? Explain your answer. **c.** Can you conclude that the variable \( \overline{x}_1 - \overline{x}_2 \) is normally distributed? Explain your answer. ### Explanation #### Part (a): Finding the Mean and Standard Deviation To find the mean and standard deviation of \( \overline{x}_1 - \overline{x}_2 \), we're given: - Mean and standard deviation for Population 1: μ1 = 55, σ1 = 24 - Mean and standard deviation for Population 2: μ2 = 55, σ2 = 40 - Sample sizes: n1 = 16, n2 = 25 To find the mean \( \mu \) of the difference in sample means \( \overline{x}_1 - \overline{x}_2 \): \[ \mu_{\overline{x}_1 - \overline{x}_2} = \mu_1 - \mu_2 \] To find the standard deviation \( \sigma \) of the difference in sample means \( \overline{x}_1 - \overline{x}_2 \): \[ \sigma_{\overline{x}_1 - \overline{x}_2} = \sqrt{\left(\frac{\sigma_1^2}{n1}\right) + \left(\frac{\sigma_2^2}{n2}\right)} \] #### Part (b): Normal Distribution in Each Population Discuss whether the variable needs to be normally distributed in each of the two populations to determine whether the sample means \( \overline{x}_1 \
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 3 images

Blurred answer
Knowledge Booster
Centre, Spread, and Shape of a Distribution
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
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 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…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
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
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman