Probability and Statistics for Engineering and the Sciences
9th Edition
ISBN: 9781305251809
Author: Jay L. Devore
Publisher: Cengage Learning
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Chapter 9.3, Problem 38E
Adding computerized medical images to a database promises to provide great resources for physicians. However, there are other methods of obtaining such information, so the issue of efficiency of access needs to be investigated. The article “The Comparative Effectiveness of Conventional and Digital Image Libraries”(J. of Audiovisual Media in Medicine, 2001: 8–15) reported on an experiment in which 13 computer proficient medical professionals were timed both while retrieving an image from a library of slides and while retrieving the same image from a computer database with a Web front end.
| Subject | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| Slide | 30 | 35 | 40 | 25 | 20 | 30 | 35 |
| Digital | 25 | 16 | 15 | 15 | 10 | 20 | 7 |
| Difference | 5 | 19 | 25 | 10 | 10 | 10 | 28 |
| Subject | 8 | 9 | 10 | 11 | 12 | 13 | |
| Slide | 62 | 40 | 51 | 25 | 42 | 33 | |
| Digital | 16 | 15 | 13 | 11 | 19 | 19 | |
| Difference | 46 | 25 | 38 | 14 | 23 | 14 |
a. Construct a comparative boxplot of times for the two types of retrieval, and comment on any interesting features.
b. Estimate the difference between true average times for the two types of retrieval in a way that conveys information about precision and reliability. Be sure to check the plausibility of any assumptions needed in your analysis. Does it appear plausible that the true average times for the two types of retrieval are identical? Why or why not?
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Chapter 9 Solutions
Probability and Statistics for Engineering and the Sciences
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