Homework Help is Here – Start Your Trial Now!
Math
Statistics
What changes the width of a confidence interval? A marketing director wants a 95% confidence interval for the mean cost of running shoes. She randomly samples 40 pairs of shoes and finds that the sample mean, î, was $122 with a sample standard deviation, s, of $27. The marketing director concluded, with 95% confidence, that between $113.36 and $130.64 contains the mean cost of all running shoes. What would change for a narrower confidence interval? Select all answers that will make the width narrower. O If the sample size decreased to 30 pairs of shoes. O If the point estimate was smaller. If she increased the confidence level to a 99% confidence level. O If the point estimate was larger. If she decreased the confidence level to a 90% confidence interval. O If the sample size increased to 50 pairs of shoes. O If the sample standard deviation was larger. O If the sample standard deviation was smaller.

What changes the width of a confidence interval? A marketing director wants a 95% confidence interval for the mean cost of running shoes. She randomly samples 40 pairs of shoes and finds that the sample mean, î, was $122 with a sample standard deviation, s, of $27. The marketing director concluded, with 95% confidence, that between $113.36 and $130.64 contains the mean cost of all running shoes. What would change for a narrower confidence interval? Select all answers that will make the width narrower. O If the sample size decreased to 30 pairs of shoes. O If the point estimate was smaller. If she increased the confidence level to a 99% confidence level. O If the point estimate was larger. If she decreased the confidence level to a 90% confidence interval. O If the sample size increased to 50 pairs of shoes. O If the sample standard deviation was larger. O If the sample standard deviation was smaller.

MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
See similar textbooks
icon
Related questions
Question
What changes the width of a confidence interval? A marketing director wants a 95% confidence interval for the mean cost of running shoes. She randomly samples 40 pairs of shoes and finds that the sample mean, ī, was $122 with a sample standard deviation, s, of $27. The marketing director concluded, with 95% confidence, that between $113.36 and $130.64 contains the mean cost of all running shoes. What would change for a narrower confidence interval? Select all answers that will make the width narrower. O If the sample size decreased to 30 pairs of shoes. If the point estimate was smaller. If she increased the confidence level to a 99% confidence level. O If the point estimate was larger. O If she decreased the confidence level to a 90% confidence interval. O If the sample size increased to 50 pairs of shoes. If the sample standard deviation was larger. O If the sample standard deviation was smaller.
Transcribed Image Text:What changes the width of a confidence interval? A marketing director wants a 95% confidence interval for the mean cost of running shoes. She randomly samples 40 pairs of shoes and finds that the sample mean, ī, was $122 with a sample standard deviation, s, of $27. The marketing director concluded, with 95% confidence, that between $113.36 and $130.64 contains the mean cost of all running shoes. What would change for a narrower confidence interval? Select all answers that will make the width narrower. O If the sample size decreased to 30 pairs of shoes. If the point estimate was smaller. If she increased the confidence level to a 99% confidence level. O If the point estimate was larger. O If she decreased the confidence level to a 90% confidence interval. O If the sample size increased to 50 pairs of shoes. If the sample standard deviation was larger. O If the sample standard deviation was smaller.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 1 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Similar 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
SEE MORE TEXTBOOKS