Exam 18: Data Analysis Overview

Four surgical procedures currently are used to install pacemakers. If the patient does not need to return for follow-up surgery, the operation is called a "clear" operation. A heart center wants to compare the 4 procedures, and collects the following numbers of patients from their own records: Which of the following tests will be the most appropriate to find out which of the 4 procedures is the most effective?

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?

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 15 insured drivers and recorded the amount of claims each made in the last 3 years. Based on this information, which of the following will you construct to learn about the average amount of claims made by the company's customer?

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. A histogram can be used to present this information.

Data on the amount of money made in a year by 1000 families in a small town were collected. You want to know if the money made is normally distributed. Which of the following would you use?

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 over 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?

A powerful women's group has claimed that men and women differ in attitudes about sexual discrimination. A group of 50 men (group 1) and 40 women (group 2) were asked if they thought sexual discrimination is a problem in the United States. Of those sampled, 11 of the men and 19 of the women did believe that sexual discrimination is a problem. Which of the following tests will you use to find out if there is any difference in attitudes about sexual discrimination?

A Paso Robles wine producer wanted to forecast the cases of merlot wine sold. The number of cases of merlot wine sold in a 28-year period was collected. Which of the following would be the most appropriate analysis to perform?

A survey was conducted to determine how people rated the quality of programming available on television. Respondents were asked to rate the overall quality from 0 (no quality at all) to 100 (extremely good quality). An ogive can be used to present this information.

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 average number of passengers being bumped over a month is the same across the 4 packages?

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.

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 quality control engineer is in charge of the manufacture of computer disks. Two different processes can be used to manufacture the disks. He suspects that the Kohler method produces a greater proportion of defects than the Russell method. He samples 150 of the Kohler and 200 of the Russell disks and finds that 27 and 18 of them, respectively, are defective. If Kohler is designated as "Group 1" and Russell is designated as "Group 2," which of the following tests will you use to find out if the Kohler method is worse than the Russell method?

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 average and standard deviation of the SSATL scores are 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 Paso Robles wine producer wanted to forecast the cases of merlot wine sold. The number of cases of merlot wine sold in a 28-year period was collected. Which of the following would be the most appropriate analysis to perform?

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 USA 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 USA medical school graduates) was obtained for each of the 4 specialties. Which of the following tests will be the most appropriate to find out if the primary specialty and the origin of medical school degree interact to affect the charges?

A researcher randomly sampled 30 graduates, 18 males and 12 females, of an MBA program and recorded data concerning their starting salaries. Of primary interest to the researcher was the effect of gender on starting salaries. Statistics of the mean salaries of the females and males in the sample were computed. The sample standard deviations suggest that the variability of starting salaries of the two groups is almost the same. Suppose the starting salaries from both groups can be considered as normally distributed. Which of the following tests will be the most appropriate?

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?

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?