Homework_Assignment_2_Solutions - Homework Assignment 2...

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Homework Assignment 2 Solutions 2.76 a. Mean ± St. Dev is 7 ± 1.7, or 5.3 to 8.7. b. Mean ± 2 St. Dev is 7 ± (2)(1.7), or 3.6 to 10.4. c. Mean ± 3 St. Dev is 7 ± (3)(1.7), or 1.9 to 12.1. 2.77 Figure for Exercise 2.77 2.78 a. z = (200 - 170)/20 = 1.5. b. z = (140 - 170)/20 = - 1.5. c. z = (170 - 170)/20 = 0. d. z = (230 - 170)/20 = 3. 2.79 a. Mean =20; Standard deviation = 1.581. b. Mean =20; Standard deviation = 0. c. Mean = 20; Standard deviation = 33.09. 2.80 a. 98–41 = 57. b. Standard deviation Range/6 = 57/6 = 9.5. 2.81 The interval is - 6.1 to 22.7 hours. The interval includes negative values, which are impossible times. Thus, the interval based an assumption of a bell-shaped curve would not reflect reality. 2.91 Outliers affect the standard deviation. This happens because the calculation uses the deviation from the mean for every value. An outlier has a large deviation from the mean, so it inflates the standard deviation. Extreme values generally do not affect the quartiles, and consequently they generally don't affect the interquartile range. Remember that a quartile is determined by counting through the ordered data to a particular location, so the exact size of the largest or smallest observations doesn't matter. 2.96
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This note was uploaded on 04/07/2008 for the course STAT 200 taught by Professor Barroso,joaor during the Spring '08 term at Pennsylvania State University, University Park.

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Homework_Assignment_2_Solutions - Homework Assignment 2...

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