BUS 308 Week 1

Week One Quiz

Complete the quiz on the assigned readings for the week.

Assignment

1.2 Below we list several variables. Which of these variables are quantitative and which are qualitative?

The dollar amount of on an accounts receivable invoice

The net profit for a company in 2009.

The stock exchange on which a companys stock is traded

The national debt of the United States in 2009.

The advertising medium (radio, television, or print) used to promote a product.

1.17 Classify each of the following qualitative variables as Ordinal or Nominative. Explain your answers.

Qualitative Variable Answer with explanation

Statistics course letter grade

Door choice on Lets Make A Deal

Television show classifications

Personal computer ownership

Restaurant rating

Income tax filing status

3.3 Calculate the mean, median, and mode of each of the following populations of numbers.

a. 9.8, 10, 10, 12.6, 11, 10, 12.8

b. 110, 120, 70, 90, 90, 100, 80, 130, 140

3.22 In order to control costs, a company wishes to study the amount of money its sales force spends entertaining clients. The following is a random sample of six entertainment expenses (dinner costs for four people) from expense reports submitted by members of the sales force.

$157 $132 $109 $145 $125 $139

a) Calculate , , and for the expense data. In addition, show that the two different formulas for calculating give same result.

b) Assuming that the distribution of entertainment expense is approximately normally distributed, calculate estimates of tolerance intervals containing 68.26 percent, 95.44 percent, and 99.73 percent of all entertainment expenses by the sales force.

c) If a member of the sales force submits an entertainment expense (dinner cost for four) of $190, should this expense be considered unusually high (and possibly worthy of investigation by the company)? Explain your answer.

d) Compute and interpret the z-score for each of the six entertainment expenses.

Discussion Questions

You are the manager at a company and are asked to present a report on the year-to-date performance of your division. What type of statistical information would you include in your report? In particular, which descriptive statistics (mean, median, standard deviation, etc.) do you think would best represent the main aspects of the performance of your division? What types of graphical presentation (histogram, dot plot, stem-and-leaf, bar chart, etc.) would you include? Explain your reasoning

Discuss how the Empirical Rule works and how it relates to the bell curve as illustrated in Figure 3.14 (a). Then, explain Chebyshevs Theorem and how it is different from the Empirical Rule. Give a specific example of a population with which the Empirical Rule might be most effective and one with which Chebyshevs Theorem might be most effective. Respond to at least two of your classmates postings.