×
Log in to StudySoup
Get Full Access to Statistics - Textbook Survival Guide
Join StudySoup for FREE
Get Full Access to Statistics - Textbook Survival Guide

In a random sample of 150 customers of a high-speed

Statistics for Engineers and Scientists | 4th Edition | ISBN: 9780073401331 | Authors: William Navidi ISBN: 9780073401331 38

Solution for problem 12E Chapter 5.2

Statistics for Engineers and Scientists | 4th Edition

  • Textbook Solutions
  • 2901 Step-by-step solutions solved by professors and subject experts
  • Get 24/7 help from StudySoup virtual teaching assistants
Statistics for Engineers and Scientists | 4th Edition | ISBN: 9780073401331 | Authors: William Navidi

Statistics for Engineers and Scientists | 4th Edition

4 5 1 276 Reviews
18
3
Problem 12E

In a random sample of 150 customers of a high-speed internet provider, 63 said that their service had been interrupted one or more times in the past month.

a. Find a 95% confidence interval for the proportion of customers whose service was interrupted one or more times in the past month.

b. Find a 99% confidence interval for the proportion of customers whose service was interrupted one or more times in the past month.

c. Find the sample size needed for a 95% confidence interval to specify the proportion to within ±0.05.

d. Find the sample size needed for a 99% confidence interval to specify the proportion to within ±0.05.

Step-by-Step Solution:

Answer:

Step 1 of 5:

            Suppose that, a random sample of 150 customers of a high-speed internet provider, 63 said that their service had been interrupted one or more times in the past month.

                 Here,   

                                     x = 63, n = 150

Step 2 of 5:     

a). Here we have to find a 95% confidence interval for the proportion of customers whose service was interrupted one or more times in the past month.

         Then,

                   

                       = 150+ 4

                       = 154.

                

               =

               = 0.4221

A 95% confidence interval for ‘p’ is given by

                          

    For a 95% confidence interval: 

  Z - value for 95% confidence interval is

   Then,

         

                                            

                                            

                                                  (0.3441, 0.5001)

  Therefore, a 95% confidence interval for the proportion of customers whose service was interrupted one or more times in the past month is (0.3441, 0.5001).

 Step 3 of 5:

 b). We need to find a 99% confidence interval for the proportion of customers whose service was interrupted one or more times in the past month.

            Then,

                   

                       = 150+ 4

                       = 154.

                

               =

               = 0.4221

A 99% confidence interval for ‘p’ is given by

                          

    For a 99% confidence interval: 

  Z - value for 99% confidence interval is

   Then,

         

                                                      

                                                    = 0.42210.1027

                                                     (0.3194, 0.5248)

 Therefore, a 99% confidence interval for the proportion of customers whose service was interrupted one or more times in the past month is (0.3194, 0.5248).

 

Step 4 of 5

Chapter 5.2, Problem 12E is Solved
Step 5 of 5

Textbook: Statistics for Engineers and Scientists
Edition: 4
Author: William Navidi
ISBN: 9780073401331

Unlock Textbook Solution

Enter your email below to unlock your verified solution to:

In a random sample of 150 customers of a high-speed

×
Log in to StudySoup
Get Full Access to Statistics - Textbook Survival Guide
Join StudySoup for FREE
Get Full Access to Statistics - Textbook Survival Guide
×
Reset your password