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).
- Fall '18
- F. TAILOKA
- Normal Distribution, Probability theory