Intro Stats
4th Edition
ISBN: 9780321826275
Author: Richard D. De Veaux
Publisher: PEARSON
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Chapter 22, Problem 45E
Grades, again In some situations where the expected cell counts are too small, as in the case of the grades given by Professors Alpha and Beta in Exercise 43, we can complete an analysis anyway. We can often proceed after combining cells in some way that makes sense and also produces a table in which the conditions are satisfied. Here, we create a new table displaying the same data, but calling D’s and F’s “Below C”:
| Prof. Alpha | Prof. Beta | |
| A | 3 | 9 |
| B | 11 | 12 |
| C | 14 | 8 |
| Below C | 12 | 3 |
- a) Find the expected counts for each cell in this new table, and explain why a chi-square procedure is now appropriate.
- b) With this change in the table, what has happened to the number of degrees of freedom?
- c) Test your hypothesis about the two professors, and state an appropriate conclusion.
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Chapter 22 Solutions
Intro Stats
Ch. 22.3 - Why do we need the control group?Ch. 22.3 - Prob. 2JCCh. 22.3 - Prob. 3JCCh. 22.3 - Prob. 4JCCh. 22.3 - Prob. 5JCCh. 22.3 - Prob. 6JCCh. 22.4 - Prob. 7JCCh. 22.4 - Prob. 8JCCh. 22.4 - Prob. 9JCCh. 22 - Human births If there is no seasonal effect on...
Ch. 22 - Bank cards At a major credit card bank, the...Ch. 22 - Prob. 3ECh. 22 - Prob. 4ECh. 22 - Customer ages An analyst at a local bank wonders...Ch. 22 - Bank cards, once more A market researcher working...Ch. 22 - Human births, last time For the data in Exercise...Ch. 22 - Prob. 8ECh. 22 - Prob. 9ECh. 22 - Prob. 10ECh. 22 - Prob. 11ECh. 22 - Prob. 12ECh. 22 - Dice After getting trounced by your little brother...Ch. 22 - MMs As noted in an earlier chapter, Mars Inc. says...Ch. 22 - Nuts A company says its premium mixture of nuts...Ch. 22 - Prob. 16ECh. 22 - NYPD and race Census data for New York City...Ch. 22 - Violence against women In its study When Men...Ch. 22 - Fruit flies Offspring of certain fruit flies may...Ch. 22 - Prob. 20ECh. 22 - Prob. 21ECh. 22 - Lottery numbers The fairness of the South African...Ch. 22 - Prob. 23ECh. 22 - Prob. 24ECh. 22 - Childbirth, part 2 In Exercise 23, the table shows...Ch. 22 - Prob. 26ECh. 22 - Prob. 27ECh. 22 - Prob. 28ECh. 22 - Prob. 29ECh. 22 - Does your doctor know? (part 4) In Exercises 24,...Ch. 22 - Prob. 31ECh. 22 - Prob. 32ECh. 22 - 33. Titanic Here is a table we first saw in...Ch. 22 - NYPD The table below shows the rank attained by...Ch. 22 - Prob. 35ECh. 22 - NYPD again Examine and comment on this table of...Ch. 22 - Cranberry juice Its common folk wisdom that...Ch. 22 - Prob. 38ECh. 22 - Montana A poll conducted by the University of...Ch. 22 - 40. Fish diet Medical researchers followed 6272...Ch. 22 - Prob. 41ECh. 22 - Working parents In April 2009, Gallup published...Ch. 22 - Grades Two different professors teach an...Ch. 22 - Full moon Some people believe that a full moon...Ch. 22 - Grades, again In some situations where the...Ch. 22 - Full moon, next phase In Exercise 44, you found...Ch. 22 - Racial steering A subtle form of racial...Ch. 22 - 48. Titanic, redux Newspaper headlines at the...Ch. 22 - Prob. 49ECh. 22 - Prob. 50ECh. 22 - Prob. 51ECh. 22 - Education by age Use the survey results in the...
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