A company that develops an automated customer service model is interested in knowing whether two versions, Version A and Version B, will get different ratings from customers. Participants in a focus group are taken through samples from both versions, then take a survey to rate each version. A summary of the data obtained from the study is given below. Assume ratings from the different surveys generally have the same standard deviation. Version A Version B Mean 33.133 28.67 15 15 Observations Pearson Correlation Hypothesized Mean Difference -0.325 0.00 df 14 t Stat -1.426 P(T<=t) one-tail 0.088 P= Ex: 1.234 t Critical one-tail -1.345 P(T<=t) two-tail 0.176 -1.761 t Critical two-tail Confidence Level 95% -3 -2 -1 3 t = Ex: 1.234 n = Ex: 9 Degrees of freedom: df = Point estimate for Version A: 1 = Ex: 1234 Point estimate for Version B: X₂ = 0 1 t=
A company that develops an automated customer service model is interested in knowing whether two versions, Version A and Version B, will get different ratings from customers. Participants in a focus group are taken through samples from both versions, then take a survey to rate each version. A summary of the data obtained from the study is given below. Assume ratings from the different surveys generally have the same standard deviation. Version A Version B Mean 33.133 28.67 15 15 Observations Pearson Correlation Hypothesized Mean Difference -0.325 0.00 df 14 t Stat -1.426 P(T<=t) one-tail 0.088 P= Ex: 1.234 t Critical one-tail -1.345 P(T<=t) two-tail 0.176 -1.761 t Critical two-tail Confidence Level 95% -3 -2 -1 3 t = Ex: 1.234 n = Ex: 9 Degrees of freedom: df = Point estimate for Version A: 1 = Ex: 1234 Point estimate for Version B: X₂ = 0 1 t=
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
![### Hypothesis Testing for the Difference Between Two Population Means
#### Scenario
A company that develops an automated customer service model seeks to determine whether two versions, Version A and Version B, will receive different ratings from customers. Participants in a focus group are exposed to samples from both versions, followed by a survey to rate each version. Below is a summary of the data obtained from the study. The study assumes that ratings from the different surveys generally have the same standard deviation.
#### Data Summary
| Statistic | Version A | Version B |
|---------------------------------|-----------|-----------|
| Mean | 33.133 | 28.67 |
| Observations | 15 | 15 |
| Pearson Correlation | -0.325 | - |
| Hypothesized Mean Difference | 0.00 | - |
| Degrees of Freedom (df) | 14 | - |
| t Stat | -1.426 | - |
| P(T≤t) one-tail | 0.088 | - |
| t Critical one-tail | -1.345 | - |
| P(T≤t) two-tail | 0.176 | - |
| t Critical two-tail | -1.761 | - |
| Confidence Level | 95% | - |
#### Explanation of the Data
- **Mean**: The average rating for Version A is 33.133 and for Version B is 28.67.
- **Observations**: Both versions had 15 participants each.
- **Pearson Correlation**: Correlation between the two ratings is -0.325.
- **Hypothesized Mean Difference**: Assumed to be 0.00 for testing purposes.
- **Degrees of Freedom (df)**: Calculated as 14.
- **t Stat**: The computed t-value for the test statistic is -1.426.
- **P(T≤t) one-tail**: The p-value for a one-tailed test is 0.088.
- **t Critical one-tail**: The critical t-value for a one-tailed test at a 95% confidence level is -1.345.
- **P(T≤t) two-tail**: The p-value for a two-tailed test is 0.176.
- **t Critical two-tail](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F27d96fb9-96d5-477b-b416-22e1c389b55a%2F6893296d-146f-4dd7-b7b6-06c4e1373371%2F14h6omj_processed.jpeg&w=3840&q=75)
Transcribed Image Text:### Hypothesis Testing for the Difference Between Two Population Means
#### Scenario
A company that develops an automated customer service model seeks to determine whether two versions, Version A and Version B, will receive different ratings from customers. Participants in a focus group are exposed to samples from both versions, followed by a survey to rate each version. Below is a summary of the data obtained from the study. The study assumes that ratings from the different surveys generally have the same standard deviation.
#### Data Summary
| Statistic | Version A | Version B |
|---------------------------------|-----------|-----------|
| Mean | 33.133 | 28.67 |
| Observations | 15 | 15 |
| Pearson Correlation | -0.325 | - |
| Hypothesized Mean Difference | 0.00 | - |
| Degrees of Freedom (df) | 14 | - |
| t Stat | -1.426 | - |
| P(T≤t) one-tail | 0.088 | - |
| t Critical one-tail | -1.345 | - |
| P(T≤t) two-tail | 0.176 | - |
| t Critical two-tail | -1.761 | - |
| Confidence Level | 95% | - |
#### Explanation of the Data
- **Mean**: The average rating for Version A is 33.133 and for Version B is 28.67.
- **Observations**: Both versions had 15 participants each.
- **Pearson Correlation**: Correlation between the two ratings is -0.325.
- **Hypothesized Mean Difference**: Assumed to be 0.00 for testing purposes.
- **Degrees of Freedom (df)**: Calculated as 14.
- **t Stat**: The computed t-value for the test statistic is -1.426.
- **P(T≤t) one-tail**: The p-value for a one-tailed test is 0.088.
- **t Critical one-tail**: The critical t-value for a one-tailed test at a 95% confidence level is -1.345.
- **P(T≤t) two-tail**: The p-value for a two-tailed test is 0.176.
- **t Critical two-tail
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Follow-up Questions
Read through expert solutions to related follow-up questions below.
Recommended textbooks for you
![MATLAB: An Introduction with Applications](https://www.bartleby.com/isbn_cover_images/9781119256830/9781119256830_smallCoverImage.gif)
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
![Probability and Statistics for Engineering and th…](https://www.bartleby.com/isbn_cover_images/9781305251809/9781305251809_smallCoverImage.gif)
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
![Statistics for The Behavioral Sciences (MindTap C…](https://www.bartleby.com/isbn_cover_images/9781305504912/9781305504912_smallCoverImage.gif)
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](https://www.bartleby.com/isbn_cover_images/9781119256830/9781119256830_smallCoverImage.gif)
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
![Probability and Statistics for Engineering and th…](https://www.bartleby.com/isbn_cover_images/9781305251809/9781305251809_smallCoverImage.gif)
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
![Statistics for The Behavioral Sciences (MindTap C…](https://www.bartleby.com/isbn_cover_images/9781305504912/9781305504912_smallCoverImage.gif)
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…](https://www.bartleby.com/isbn_cover_images/9780134683416/9780134683416_smallCoverImage.gif)
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
![The Basic Practice of Statistics](https://www.bartleby.com/isbn_cover_images/9781319042578/9781319042578_smallCoverImage.gif)
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](https://www.bartleby.com/isbn_cover_images/9781319013387/9781319013387_smallCoverImage.gif)
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman