1. Income is an example of a variable that uses the:

1. Ratio scale
2. Interval scale
3. Nominal scale
4. Ordinal scale

2. The following table shows the starting salaries of a sample of recent business graduates.

Income (In $1,000s)	Number of Graduates
15 - 19	40
20 - 24	70
25 - 29	80
30 - 34	18
35 - 39	12

A) What percentage of graduates in the sample had starting salaries of at least $30,000?

______________

B) Of the graduates in the sample, what percentage had starting salaries of less than $25,000?

______________

C) Based on this sample, what percentage of all business graduates do you estimate to have starting salaries of at least $20,000?

_______________

3. Prompts i-v below are based on the following: Michael's Compute-All, a national computer retailer, has kept a record of the number of laptop computers they have sold for a period of 80 days. Their sales records are shown here:

	Number of Laptops Sold	Number of Days
	0 - 19	5
	20 - 39	15
	40 - 59	40
	60 - 79	20
	80 - 99	10
		Total 90

i. The class width of the above distribution is

a. 0 to 100

b. 80

c. 20

d. 5

ii. The lower limit of the first class is

a. 5

b. 0

c. 80

d. 20

iii. If one develops a cumulative frequency distribution for the above data, the last class will have a frequency of

a. 10

b. 100

c. 0 to 100

d. 90

iv. The percentage of days in which the company sold at least 40 laptops is

a. 66.7%

b. 90.0%

c. 77.8%

d. 44.4%

v. The number of days in which the company sold less than 60 laptops is

a. 20

b. 30

c. 50

d. 60

4. A group of students had dinner at a local restaurant. The total bill for the dinner was $414.70. Each student paid his/her equal share of the bill, which was $18.85. How many students were at the dinner?

a. 4

b. 415

c. 22

d. 19

5. When the smallest and largest percentage of items are removed from a data set and the mean is computed, the mean of the remaining data is:

a. the median

b. the mode

c. the trimmed mean

d. any of the above

6. Compute the weighted mean for the following data.

xi	Weight (wi)
9	10
8	12
5	4
3	5
2	3

_____________________

7. The median is a measure of:

a. relative dispersion

b. absolute dispersion

c. central location

d. relative location

8. The 75th percentile is referred to as the:

a. first quartile

b. second quartile

c. third quartile

d. fourth quartile

9. The value which has half of the observations above it and half the observations below it is called the:

a. range

b. median

c. mean

d. mode

10. Prompts a-c below are based on the following: a local university administers a comprehensive examination to the recipients of a B.S. degree in Business Administration. A sample of examinations are selected at random and scored. The results are shown below.

Grade

93

65

80

97

85

87

97

60

A. The mean___________________

B. The median____________

C. The mode__________________

11. The variance of a sample of 81 observations equals 64. The standard deviation of the sample equals:

a. 9

b. 4096

c. 8

d. 6561

14. This denotes the number of standard deviation's that a data value is from the mean:

1. Mu
2. Z-score
3. A Chebyshev

15. I According to the empirical rule for a normal distributions (bell shaped), what percentage of the values are within +/- 3 standard deviations from the mean?

1. 95.44%
2. 68.26%
3. 99.72%
4. 33.33%

16. A numerical measure of linear association between two variables is the

a. variance

b. covariance

c. standard deviation

d. coefficient of variation

17. A coefficient of -1 indicates that:

a. a change in one variable will predict a change in the same direction in the second.

b. a change in one variable predicts a change in the opposite direction in the second.

c. changes in each variable increases or decreases in tandem

12. Prompts a-e below are based on the following: a sample of 9 mothers was taken. The mothers were asked the age of their oldest child. You are given their responses here: \"Human\" a. Compute the mean. 2%: n x b. Given the variance 52 = 17.78, compute the standard deviation, 5. \"J? c. Determine the 25th percentile. i= (rs/1g); d. Determine the median. e. Determine the range. Frequency 3 .'l 250 '50 1250 \"50 2250 2750 3250 3'350 1250 1-?50 5250 5'35!) 625!) 13. The distribution pictured above exhibits a skewness. a. Askew b Positive c. Negative d Zero