Chapter 3

1. A park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes; mean = 114.15): Remember to briefly discuss the importance of each of your results.

124, 118, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118

1.What is the 65^thpercentile? 90th percentile? What do these mean?

2.What are the upper and lower limits?

3.What is the 3^rdquartile? What is the IQR?

4.What is the variance? Standard Deviation?

5.What do the above quartiles represent and how useful is this analysis?

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2.

The following data show the yearly salaries of some recent MBA graduates.

EMBA Student

Salary (in $1,000)

A

88

B

97

C

90

D

110

E

114

F

98

G

92

H

95

a.Compute the mean yearly salary in dollars.

b.Compute the standard deviation in dollars.

c.Compute the 75th percentile in dollars. What does the value that you have

determined indicate? What is the 10^th percentile?

d. What does the Variance and Standard deviation represent in this problem?

e.What is the Coefficient of Variance (CV)? What does it indicate?

4. Given the following sample data:

x

420

610

625

500

400

450

550

650

480

565

y

2.80

3.60

3.75

3.00

2.50

2.70

3.50

3.90

2.95

3.30

a. Calculate the covariance and the correlation coefficient.

b. Comment on the relationship between x and y.

c. What do these statistics tell you about the relationship between x and y?

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