Exam 18: A Roadmap for Analyzing Data

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?

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?

The use of preservatives by food processors has become a controversial issue. Suppose 2 preservatives are extensively tested and determined safe for use in meats. A processor wants to compare the preservatives for their effects on retarding spoilage. They will choose to use the preservative that can keep the meat fresh for the longest amount of time. Suppose 15 cuts of fresh meat are treated with preservative I and 15 are treated with preservative II, and the number of hours until spoilage begins is recorded for each of the 30 cuts of meat. Suppose the variability of the number of hours until spoilage is the same for meat treated by both preservatives but the normal probability plots reveal that the number of hours until spoilage is right-skewed for the 15 cuts treated by preservative I and left-skewed for the 15 cuts treated with preservative II. Which of the following tests will be the most appropriate?

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?

An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4) are commercially available. The airline will choose the package that bumps as few passengers, on the average, as possible during a month. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks. (A total of 20 weeks was included in the experiment.) Which of the following tests will be the most appropriate?

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. He has also found out special types do have an impact on average charges. Which of the following tests will be the most appropriate to find out which primary specialty has the highest charges?

Data on the amount of money made in a year by 1,000 families in a small town were collected. You want to know the difference in the amount of money made in that year by the middle 50% of the 1,000 families. Which of the following would you compute?

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.

A realtor wants to compare the variability of sales-to-appraisal ratios of residential properties sold in four neighborhoods (A, B, C, and D). Four properties are randomly selected from each neighborhood and the ratios recorded for each were collected. Which of the following tests will be the most appropriate?

At a meeting of information systems officers for regional offices of a national company, a survey was taken to determine the number of employees the officers supervise in the operation of their departments, where X is the number of employees overseen by each information systems officer. A stem-and-leaf display can be used to present this information.

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is more than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Which of the following tests will you perform to help her make a decision?

A sample of 100 fuses from a very large shipment is found to have 10 that are defective. Based on this information, which of the following will you construct to learn about the proportion of fuses that are defective?

An investor wanted to forecast the price of a certain stock. He collected the mean daily price for the stock over the past 10 years. Which of the following would be the most appropriate analysis to perform?

Data on the amount of time spent studying for a particular exam at a high school were collected for 150 students. You want to know at least how much time half of the students spent studying for that exam. 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?

A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging. In order to determine if his suspicion is correct, he contacts a second supplier and asks for the prices on various identical materials. He wants to compare these prices with those of his primary supplier. He collected data on 6 different materials from both suppliers. He believes that the differences are normally distributed. Which of the following tests will be the most appropriate?

A supplier of silicone sheets for producers of computer chips wants to evaluate her manufacturing process. She takes samples of size 5 from each day's output and counts the number of blemishes on each silicone sheet for 20 days consecutive days. 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?

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 variance on the number of passengers that are bumped is found to be roughly the same for the 4 packages. 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?

Every spring semester, the School of Business coordinates with local business leaders a luncheon for graduating seniors, their families, and friends. Corporate sponsorship pays for the lunches of each of the seniors, but students have to purchase tickets to cover the cost of lunches served to guests they bring with them. Data on the number of guests each graduating senior invited to the luncheon and the number of graduating seniors in each category were collected. You want to know the most popular number of guests brought by the graduating seniors. Which of the following will you compute?