Exam 19: Statistical Analysis Scenarios and Distributions

Data on the amount of money made in a year by 1000 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 1000 families. 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 average 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. A histogram can be used to present this information.

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?

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?

The opinions (classified as "for," "neutral" or "against") of a sample of 200 people broken down by gender about the latest congressional plan to eliminate anti-trust exemptions for professional baseball. You can present this information using a scatter plot.

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: Procedure A B C D Total Clear 27 41 21 7 96 Return 11 15 9 11 46 Total 38 56 30 18 142 Which of the following tests will be the most appropriate to find out which of the 4 procedures is the most effective?

A realtor wants to compare the variability of sales-to-appraisal ratios of residential properties sold in four neighborhoods (A, B, C, andD) 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?

An Undergraduate Study Committee of 6 members at a major university is to be formed from a pool of faculty of 18 men and 6 women. Which of the following distributions would you use to figure out the probability that half of the members will be women?

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?

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?

An agronomist wants to compare the crop yield of 3 varieties of chickpea seeds. She plants all 3 varieties of the seeds on each of 5 different patches of fields. She then measures the crop yield in bushels per acre. She has found out that the crop yield from the 3 varieties of seeds has very skewed distribution. Which of the following tests will be the most appropriate to find out if the different patches is advantageous in reducing the random error?

The probability of receiving a 911 call on a university campus is the same every day. The probability of having received a 911 call on a single day does not change the probability of receiving a 911 call on any other day. Which of the following distributions would you use to figure out the probability that a 911 call will be received next day?

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.

Data on the amount of money made in a year by 1000 families in a small town were collected. You want to know how much each family will get if the money made by all the 1000 families is pooled together and then evenly redistributed back to them. Which of the following would you compute?

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?

The amount of juice that can be squeezed from a randomly selected orange out a box of oranges with approximately the same size can most likely be modeled by which of the following distributions?

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 probability that a particular brand of smoke alarm will function properly and sound an alarm in the presence of smoke is 0.8. A batch of 100,000 such alarms was produced by independent production lines. Which of the following distributions would you use to figure out the probability that at least 90,000 of them will function properly in case of a fire?

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?