![Basic Business Statistics](https://www.bartleby.com/isbn_cover_images/9780134684840/9780134684840_largeCoverImage.gif)
Concept explainers
An insurance company has the business objective of reducing the amount of time it takes to approve for life insurance, the approval process consists of underwriting, which includes a review of the application, a medical information bureau check, possible requests for additional medical information and medical exams, and a policy compilation stage in which the policy pages are generated and sent for delivery. The ability to deliver approved policies to customer in a timely manner is critical to the profitability of this service. During a period of one month, you collect a random sample of 27 approved policies and store total processing times, in days, in insurance.
a. In the past, the
b. What assumption about the population distribution is needed in order to conduct the t test
in (a)?
c. Construct a boxplot or a normal probability plot to evaluate the assumption made in (b).
d. Do you think the assumption needed in order to conduct the t (a) valid? Explain.
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 9 Solutions
Basic Business Statistics
- Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the coefficient of variation for each fund. Round your answers to the nearest tenth. x: 14 0 37 21 35 23 24 -14 -14 -17 y: 8 -2 29 17 22 17 17 -2 -3 -8arrow_forwardWhat percentage of the general U.S. population have bachelor's degrees? Suppose that the Statistical Abstract of the United States, 120th Edition, gives the following percentage of bachelor’s degrees by state. For convenience, the data are sorted in increasing order. 17 18 18 18 19 20 20 20 21 21 21 21 21 22 22 22 22 22 23 23 24 24 24 24 24 25 25 25 25 26 26 26 26 26 26 27 27 27 28 28 28 29 29 31 31 32 32 34 35 38 Illinois has a bachelor's degree percentage rate of about 18%. Into what quartile does this rate fall?arrow_forwardWhat percentage of the general U.S. population have bachelor's degrees? Suppose that the Statistical Abstract of the United States, 120th Edition, gives the following percentage of bachelor’s degrees by state. For convenience, the data are sorted in increasing order. 17 18 18 18 19 20 20 20 21 21 21 21 21 22 22 22 22 22 23 23 24 24 24 24 24 25 25 25 25 26 26 26 26 26 26 27 27 27 28 28 28 29 29 31 31 32 32 34 35 38 Illinois has a bachelor's degree percentage rate of about 18%. Into what quartile does this rate fall?arrow_forward
- Find the range for the following sample data. x 23 17 11 30 27arrow_forwardDo bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the sample mean for x and for y. Round your answer to the nearest tenth. x: 11 0 36 22 34 24 25 -11 -11 -22 y: 9 -3 28 14 23 16 14 -3 -4 -9arrow_forwardDo bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the range for variable y. X 12 0 36 21 35 23 24 -12 -12 -21 Y 10 -2 26 15 22 18 15 -2 -3 -10arrow_forward
- Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the range for variable y. X 12 0 36 21 35 23 24 -12 -12 -21 Y 10 -2 26 15 22 18 15 -2 -3 -10arrow_forwardDo bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the range for variable x. X 15 0 37 23 33 25 26 -15 -15 -23 Y 6 -1 28 18 24 17 18 -1 -2 -6arrow_forward7.16. If the probability density of X is given by g kx³ for x>0 f(x) = (1+2x)6 0 10-01, elsewhere trolls inf ( 2X density of the random variable Y = where k is an appropriate constant, find the probability 1+2X distribution of Y, and thus determine the value of k. 7 Identify thearrow_forward
- 7.1. If X has an exponential distribution with the parameter 0, use the distribution function technique to find the probability density of the random variable Y = ln X. bilaga in dwreatarrow_forward3. Pleasearrow_forwardWhat does the margin of error include? When a margin of error is reported for a survey, it includes a. random sampling error and other practical difficulties like undercoverage and non-response b. random sampling error, but not other practical difficulties like undercoverage and nonresponse c. practical difficulties like undercoverage and nonresponse, but not random smapling error d. none of the above is corretarrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman
![Text book image](https://www.bartleby.com/isbn_cover_images/9781119256830/9781119256830_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305251809/9781305251809_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305504912/9781305504912_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780134683416/9780134683416_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781319042578/9781319042578_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781319013387/9781319013387_smallCoverImage.gif)