Exam 18: A Roadmap for Analyzing Data

Data on the amount of money made in a year by 1,000 families in a small town were collected. You want to know how much each family will get if the money made by all the 1,000 families is pooled together and then evenly redistributed back to them. Which of the following would you compute?

A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent. The pollster wishes to see if the percentage favoring the incumbent candidate is too erratic. Which of the following would be the most appropriate analysis to perform?

Data on the amount of time spent studying and the exam score of 150 students at a high school were collected. You want to know if a student's exam score is linearly related to the amount of time spent on studying. Which of the following would you compute?

A physician and president of a Tampa Health Maintenance Organization (HMO)are attempting to show the benefits of managed health care to an insurance company. The physician believes that certain types of doctors are more cost-effective than others. To investigate this, the president obtained independent random samples of 20 HMO physicians from each of 4 primary specialtiesGeneral Practice (GP), Internal Medicine (IM), Pediatrics (PED), and Family Physicians (FP)and recorded the total charges per member per month for each. A second variable which the president believes influences total charges per member per month is whether the doctor is a foreign or US medical school graduate. To investigate this, the president also collected data on 20 foreign medical school graduates in each of the 4 primary specialty types described above. So information on charges for 40 doctors (20 foreign and 20 US medical school graduates)was obtained for each of the 4 specialties. The president has already found out that specialty types and origin of the medical degree do not interact to affect the charges. Which of the following tests will be the most appropriate to find out if the primary specialty affects the charges?

The director of a training program wanted to know if a one-week orientation would change the perception of potential clients who would perceive the program as being good. He collected information on the number of clients who would rate the program as being good before and after the orientation. Which of the following tests will be the most appropriate?

A major Blu-ray rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with Blu-ray players. It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have Blu-ray players. Which of the following tests will be the most appropriate?

A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim, a random sample of 100 doctors results in 83 who indicate that they recommend aspirin. Which of the following tests will you perform?

A sample of 200 students at a Big-Ten university was taken after the midterm to ask whether they went bar hopping the weekend before the midterm or spent the weekend studying, and whether they did well or poorly on the midterm. You can use a contingency table to present this information.

Are Japanese managers more motivated than American managers? A randomly selected group of 100 managers from each group were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The mean and standard deviation of the SSATL scores were computed. The standard deviations of the SSATL scores suggest that the standard deviation from the two groups is very different. Which of the following tests will be the most appropriate?

A manager of a product sales group believes the number of sales made by an employee depends on how many years that employee has been with the company and how he/she scored on a business aptitude test. A random sample of 38 employees was selected to collect data on their number of sales, number of years with the company and scores on a business aptitude test. Which of the following would you perform to draw conclusion on the belief?

A certain type of rare gem serves as a status symbol for many of its owners. In theory, for low prices, the demand increases and it decreases as the price of the gem increases. However, experts hypothesize that when the gem is valued at very high prices, the demand increases with price due to the status owners believe they gain in obtaining the gem. Data on price and quantity sold were collected for a sample of 35 rare gems of this type. Which of the following would be the most appropriate analysis to perform?

An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4)are commercially available. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks and data on the number of passengers that are bumped over a month are collected. (A total of 20 weeks was included in the experiment.)The variability of the number of passengers that are bumped is found to be roughly the same for the 4 packages. The distribution on the number of passengers that are bumped has been found out to be right-skewed for package 1 and 4, left-skewed for package 2 and normal for package 3. Which of the following tests will be the most appropriate to find out if the mean number of passengers being bumped over a month is the same across the 4 packages?

An entrepreneur is considering the purchase of a coin-operated laundry. The current owner claims that over the past 5 years, the mean daily revenue was $675 with a standard deviation of $75. A sample of 30 days reveals a daily mean revenue of $625 and a standard deviation of $70. Which of the following tests will be the most appropriate?

An insurance company evaluates many variables about a person before deciding on an appropriate rate for automobile insurance. A representative from a local insurance agency selected a random sample of 100 insured drivers and recorded X, the amount of claims each made in the last 3 years. A Pareto chart can be used to present this information.