An automobile dealer has an inventory of 200 used cars. To estimate the mean mileage of this inventory, she intends to take a simple random sample of used cars. Previous studies suggest that the population standard deviation is 10,000 miles. A 90% confidence interval for the population mean must extend 2,500 miles on each side of its sample estimate. How large of a sample size is necessary to satisfy this requirement? The minimum sample size needed to satisfy the requirement is (Round un to the nearest whole pumber )
An automobile dealer has an inventory of 200 used cars. To estimate the mean mileage of this inventory, she intends to take a simple random sample of used cars. Previous studies suggest that the population standard deviation is 10,000 miles. A 90% confidence interval for the population mean must extend 2,500 miles on each side of its sample estimate. How large of a sample size is necessary to satisfy this requirement? The minimum sample size needed to satisfy the requirement is (Round un to the nearest whole pumber )
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
could you please explain both of them? I didn't understand

Transcribed Image Text:An automobile dealer has an inventory of 200 used cars. To estimate the mean mileage of this inventory, she intends to take a simple random sample of used cars.
Previous studies suggest that the population standard deviation is 10,000 miles. A 90% confidence interval for the population mean must extend 2,500 miles on each
side of its sample estimate. How large of a sample size is necessary to satisfy this requirement?
The minimum sample size needed to satisfy the requirement is
(Round up to the nearest whole number.)

Transcribed Image Text:A random sample of six salespersons that attended a motivational course on sales techniques was monitored
three months before and three months after the course. The table shows the values of sales (in thousands of
dollars) generated by these six salespersons in the two periods.
Salesperson Before the Course After the Course
217
242
284
292
3
196
192
4
330
351
5
158
190
198
179
Assume that the population distributions are normal. Find an 80% confidence interval for the difference between the two population means.
What is the confidence interval estimate of the mean difference (uafter - Hbefore)?
(Round to two decimal places as needed.)
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps with 1 images

Knowledge Booster
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.Recommended textbooks for you

MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc

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
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning

MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc

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
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning

Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON

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
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman