You may use the extra sheets of paper to solve the following questions, but you please report your results and conclusions in the space provided. Whenever possible, show your work for potential partial credit. NOTE: When performing numerical calculations, keep at least 4 digits after a decimal. (I.e., do NOT round .2265 to .23 or .227) BUDGET YOUR TIME WISELY!

1. A survey of undergraduates designed to gauge political interest is given in the campus center of a small liberal arts college. The following table provides a sample of the database.

Name	Age	Gender (F=0, M=1)	Undergraduate Degree	Annual Salary	Do you own a sewing kit? (Y=1, N=0)	Number of Children
Lindsay	25	0	Economics	$300,000	0	0
Josh	31	1	Psychology	$67,000	0	1
Elliott	19	1	Statistics	$123,500	0	2
Terri	33	0	Advertising	$99,300	0	3
Schmutte	87	1	Home Economics	$12,100	1	8

a. What are the elements in the data set? (2 points)

b. How many variables are in the data set? (2 points)

c. How many observations are in the data set? (3 points)

d. Which of the variables are qualitative and which are quantitative variables? Why did you pick these as qualitative or quantitative? (4 points)

2. A professor of Economics at a local college has just finished compiling grades for the last semester’s Statistics course and has made the bar graph below. Use statistical inference to comment upon college grades. Make sure you clarify which groups about which you can or cannot infer anything.

3. Corporate Resources Group conducted a study of several cities across the United States to compare cost of living. More than 200 items were used to compile an index measuring the cost of living. These items included housing, food, clothing, cars, drink and entertainment. The cities selected and their ratings are presented below.

City	Cost-of-Living Rating
Atlanta	72
Boston	82
Chicago	88
Cleveland	70
Detroit	81
Honolulu	87
Houston	85
Lexington, KY	71
Los Angeles	88
San Francisco	86
St. Louis	79
Miami	89
Minneapolis	74
Pittsburgh	74
Portland, OR	67
New York	100
Seattle	74
Washington	83
White Plains, NY	86
Winston-Salem	70

a. In the space to the right of this table, construct a frequency and relative frequency distribution with 7 classes. (6 points)

b. What specific conclusions can you make with this frequency distribution that may be very difficult to make just using the raw data? (6 points)

4. Describe a scenario where using the median might be more appropriate than using a mean to describe the central tendency of a sample of data. In general terms, what does the 90^th percentile represent as a measure of location? (10 points)

5. The prices ($) of two stocks are shown to vary over a 6-month period.

Month	Stock A	Stock B
July	$13	$37
Aug	16	48
Sept	11	33
Oct	10	30
Nov	9	33
Dec	13	39

a. Calculate the mean and median stock prices for both stocks. For these companies, what does each represent? (6 points)

b. Create a measure of the relative variability of the stocks. Which stock appears to be more stable? (8 points)

6. How and why would you use the Empirical Rule to detect an “outlier”? Begin your explanation by defining an outlier. (12 points)

7. Suppose a marketing firm surveyed 80 father-son pairs and asked about their college educations. The responses are summarized below.

		Son		Totals
Father		Attended College	Did Not Attend College
	Attended College	18	7	25
	Did Not Attend College	22	33	55
Totals		40	40	80

a. For each group, what are the marginal probabilities of attending college? (4 points)

b. What is the joint probability of father and son both attending college? Of both not attending college? (4 points)

c. Given the father did not attend college, what is the probability that the son did attend college? (4 points)

d. Is attending the college by the son independent of whether his father attended college? Are they mutually exclusive? Explain, using probability values. (8 points)

8. Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. The mean arrival rate is 10 passengers per minute.

a. What is the probability of no arrivals in a one-minute period? (3 points)

b. What is the probability of at least one arrival in a 15 second period? (4 points)

9. Suppose historical data shows that a student who majors in Economics will receive 3 job offers for every 8 job interviews. If a student interviews with 10 different companies, what is the probability that he/she will receive exactly 4 job offers? What is the probability that he/she will receive at least one job offer? (8 points)