Intro Stats
4th Edition
ISBN: 9780321825278
Author: Richard D. De Veaux, Paul F. Velleman, David E. Bock
Publisher: PEARSON
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Chapter 22, Problem 30E
Does your doctor know? (part 4) In Exercises 24, 26, and 28, we’ve tested a hypothesis about whether the use of statistics in NEJM medical articles has changed over time. The table shows the test’s residuals.
| 1978–79 | 1989 | 2004–05 | |
| No Stats | 3.39 | –1.68 | –2.48 |
| Stats | –1.64 | 0.81 | 1.20 |
- a) Show how the residual for the 1989/No cell was calculated.
- b) What can you conclude from the patterns in the standardized residuals?
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For unemployed persons in the United States, the average number of months of unemployment at the end of December 2009 was approximately seven months (Bureau of Labor Statistics, January 2010). Suppose the following data are for a particular region in upstate New York. The values in the first column show the number of
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(x)
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1
2
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4
5
6
7
8
9
10
b. Show that your probability distribution satisfies the conditions for a valid discrete probability distribution.
The input in the box below will not be graded, but may be reviewed and considered by your instructor.
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c. What is the probability that a…
West Virginia has one of the highest divorce rates in the nation, with an annual rate of approximately 5 divorces per 1000 people (Centers for Disease Control and Prevention website, January 12, 2012). The Marital Counseling Center, Inc. (MCC) thinks that the high divorce rate in the state may require them to hire additional staff.
Working with a consultant, the management of MCC has developed the following probability distribution for x = the number of new clients for marriage counseling for the next year.
Excel File: data05-19.xls
x
10
f(x)
.05
20
30
.10
.10
40
.20
50
60
.35
.20
a. Is this probability distribution valid?
- Select your answer-
Explain.
f(x)
Σf(x)
Select your answer
Select your answer
b. What is the probability MCC will obtain more than 30 new clients (to 2 decimals)?
c. What is the probability MCC will obtain fewer than 20 new clients (to 2 decimals)?
d. Compute the expected value and variance of x.
Expected value
Variance
clients per year
squared clients per year
For unemployed persons in the United States, the average number of months of unemployment at the end of December 2009 was approximately seven months (Bureau of Labor Statistics, January 2010). Suppose the following data are for a particular region in upstate New York. The values in the first column show the number of
months unemployed and the values in the second column show the corresponding number of unemployed persons.
Months
Unemployed
Number
Unemployed
1
1029
2
1686
3
2269
4
2675
5
3487
6
4652
7
4145
8
3587
9
2325
10
1120
Let x be a random variable indicating the number of months a person is unemployed.
a. Use the data to develop an empirical discrete probability distribution for x (to 4 decimals).
(x)
f(x)
1
2
3
4
5
6
7
8
9
10
b. Show that your probability distribution satisfies the conditions for a valid discrete probability distribution.
The input in the box below will not be graded, but may be reviewed and considered by your instructor.
c. What is the probability that a person…
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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