Essentials of Business Analytics (MindTap Course List)
2nd Edition
ISBN: 9781305627734
Author: Jeffrey D. Camm, James J. Cochran, Michael J. Fry, Jeffrey W. Ohlmann, David R. Anderson
Publisher: Cengage Learning
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Chapter 2, Problem 22P
The results of a national survey showed that on average, adults sleep 6.9 hours per night. Suppose that the standard deviation is 1.2 hours and that the number of hours of sleep follows a bell-shaped distribution.
- a. Use the
empirical rule to calculate the percentage of individuals who sleep between 4.5 and 9.3 hours per day. - b. What is the z-value for an adult who sleeps 8 hours per night?
- c. What is the z-value for an adult who sleeps 6 hours per night?
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Teenage obesity (O), and weekly fast-food meals (F), among some selected Mississippi teenagers are:
Name Obesity (lbs) # of Fast-foods per week
Josh
185
10
Karl
172
8
Terry
168
9
Kamie
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154
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(a) Compute the variance of Obesity, s²o, and the variance of fast-food meals, s², of this data. [Must show full work].
(b) Compute the Correlation Coefficient between O and F. [Must show full work].
(c) Find the Coefficient of Determination between O and F. [Must show full work].
(d) Obtain the Regression equation of this data. [Must show full work].
(e) Interpret your answers in (b), (c), and (d). (Full explanations required).
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The average miles per gallon for a sample of 40 cars of model SX last year was 32.1, with a population standard deviation of 3.8. A sample of 40 cars from this year’s model SX has an average of 35.2 mpg, with a population standard deviation of 5.4.
Find a 99 percent confidence interval for the difference in average mpg for this car brand (this year’s model minus last year’s).Find a 99 percent confidence interval for the difference in average mpg for last year’s model minus this year’s. What does the negative difference mean?
A special interest group reports a tiny margin of error (plus or minus 0.04 percent) for its online survey based on 50,000 responses. Is the margin of error legitimate? (Assume that the group’s math is correct.)
Chapter 2 Solutions
Essentials of Business Analytics (MindTap Course List)
Ch. 2 - A Wall Street Journal subscriber survey asked 46...Ch. 2 - The following table contains a partial list of...Ch. 2 - Ohio Logistics manages the logistical activities...Ch. 2 - A partial relative frequency distribution is...Ch. 2 - In a recent report, the top five most-visited...Ch. 2 - In a study of how chief executive officers (CEOs)...Ch. 2 - Consumer complaints are frequently reported to the...Ch. 2 - Reports have found that many U.S. adults would...Ch. 2 - Consider the following data: a. Develop a...Ch. 2 - Consider the following frequency distribution....
Ch. 2 - The owner of an automobile repair shop studied the...Ch. 2 - Approximately 1.65 million high school students...Ch. 2 - Consider a sample with data values of 10, 20, 12,...Ch. 2 - Consider a sample with data values of 27, 25, 20,...Ch. 2 - Consider a sample with data values of 53, 55, 70,...Ch. 2 - If an asset declines in value from 5,000 to 3,500...Ch. 2 - Suppose that you initially invested 10,000 in the...Ch. 2 - The average time that Americans commute to work is...Ch. 2 - Suppose that the average waiting time for a...Ch. 2 - According to the National Education Association...Ch. 2 - Return to the waiting times given for the...Ch. 2 - The results of a national survey showed that on...Ch. 2 - Suppose that the national average for the math...Ch. 2 - Five observations taken for two variables follow....Ch. 2 - The scatter chart in the following figure was...Ch. 2 - The economic downturn in 20082009 resulted in the...Ch. 2 - Heavenly Chocolates manufactures and sells quality...
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