Elementary statistics 13th edition triola solutions manual 1

Page 1

Chapter 7: Estimating Parameters and Determining Sample Sizes 81

Solution Manual for Elementary Statistics 13th Edition by Triola ISBN 0134462459 9780134462455 Full download link at: Solution manual: https://testbankpack.com/p/solution-manual-for-elementary-statistics13th-edition-by-triola-isbn-0134462459-9780134462455/ Chapter 7: Estimating Parameters and Determining Sample Sizes Section 7-1: Estimating a Population Proportion 1. The confidence level (such as 95%) was not provided. 2. When using 14% to estimate the value of the population percentage for those who prefer chocolate pie, the maximum likely difference between 14% and the true population percentage is four percentage points, so the interval from 14%  4%  10% to 14%  4%  18% is likely to contain the true population percentage. 3.

4.

p̂  0.14 is the sample proportion; q̂  0.86 (found from evaluating 1 p̂ ); n  1000 is the sample size; E  0.04 is the margin of error; p is the population proportion, which is unknown. The value of  is 0.05. The 95% confidence interval will be wider than the 80% confidence interval. A confidence interval must be wider in order for us to be more confident that it captures the true value of the population proportion. (Think of estimating the age of a classmate. You might be 90% confident that she is between 20 and 30, but you might be 99.9% confident that she is between 10 and 40.)

5.

z0.05  1.645

7.

z0.0025  2.81

6.

z0.005  2.576 (Table: 2.575)

8.

z0.01  2.33

9.

p̂ 

10. p̂ 

0.0434  0.217

 0.130 and E 

2 0.179  0.321

 0.250 and E  2 11. 0.0169  p  0.143

0.217  0.0434

2 0.321 0.179

 0.087; 0.130  0.087

 0.071; 0.250  0.071

2

12. 0.270  0.073  p  0.270  0.073, or 0.197  p  0.343 13. a.

p̂  33 362  0.0912 33

b. E  z /2 c.

329

p̂q̂  1.96 362 362  0.0297 n 362 p̂  E  p  p̂  E

0.0912  0.0297  p  0.0912  0.0297 0.0615  p  0.121 d. We have 95% confidence that the interval from 0.0615 to 0.121 actually does contain the true value of the population proportion of McDonald’s drive-through orders that are not accurate. 14. a.

p̂  153 5924  0.0258

b. E  z /2 c.

 2.58

153 5924

771 5924

5924 p̂  E  p  p̂  E

 0.00531

0.0258  0.00531  p  0.0258  0.00531 Copyright © 2018 Pearson Education, Inc.


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