GBS 541
Homework #2
7/4/2019
Due: 15/4/2019
Use formulas, calculations and tables, unless stated otherwise. (Show the formulas
and how you arrive at your solution) You can use MegaStat/Excel to check you
answers
Question 1
The Dow Jones Travel Index reported what business travelers pay for hotel rooms per
night in major U.S. cities (
The Wall Street Journal,
January 16, 2004). The average hotel
room rates for 20 cities are as follows:
Atlanta
$163
Minneapolis
$125
Boston
177
New Orleans
167
Chicago
166
New York
245
Cleveland
126
Orlando
146
Dallas
123
Phoenix
139
Denver
120
Pittsburgh
134
Detroit
144
San Francisco
167
Houston
173
Seattle
162
Los Angeles
160
St. Louis
145
Miami
192
Washington, D.C. 207
a.
What is the mean hotel room rate?
b.
What is the median hotel room rate?
c.
What is the mode?
d.
What is the first quartile?
e.
What is the third quartile
?
Question 2
Annual sales, in millions of dollars, for 21 pharmaceutical companies
follow.
8408 1374 1872 8879 2459 11413
608
14138
6452 1850 2818 1356
10498
7478 4019 4341 739
2127
3653 5794 8305
a.
Provide a five-number summary.
b.
Compute the lower and upper limits.
c.
Do the data contain any outliers?
d.
Johnson & Johnson’s sales are the largest on the list at $14,138
million. Suppose a data entry error (a transposition) had been
1

made and the sales had been entered as $41,138 million. Would
the method of detecting outliers in part (c) identify this problem
and allow for correction of the data entry error?
e.
Show a box plot.
Question 3
The
Los Angeles Times
regularly reports the air quality index for various areas of
Southern California. A sample of air quality index values for Pomona provided the
following data:
28, 42, 58, 48, 45, 55, 60, 49, and 50.
a.
Compute the range and interquartile range.
b.
Compute the sample variance and sample standard deviation.
c.
A sample of air quality index readings for Anaheim provided a sample mean of
48.5, a sample variance of 136, and a sample standard deviation of 11.66. What
comparisons can you make between the air quality in Pomona and that in
Anaheim on the basis of these descriptive statistics?
Question 4
The Energy Information Administration reported that the mean retail
price per gallon of regular grade gasoline was $2.05 (Energy
Information Administration, May 2009).

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