Chapter 4.4, Problem 45E

For the travel time distribution given in the previous exercise, the approximate mean and standard deviation for the travel time distribution are 27 minutes anti 24 minutes, respectively. Based on this mean and standard deviation anti the fact that travel time cannot be negative, explain why the travel time distribution could not be well approximated by a normal curve.

The U.S. Census Bureau (2000 census) reported the following relative frequency distribution for travel time to work for a large sample of adults who did not work at home:

1. a. Draw’ the histogram for the travel lime distribution. In constructing the histogram, assume that the last interval in the relative frequency distribution (90 or more) ends at 200; so the last interval is 90 to <200. Be sure to use the density scale to determine the heights of the bars in the histogram because not all the intervals have the same width. (Hint: Histograms were covered in Chapter 3.)
2. b. Describe the interesting features of the histogram from Part (a), including center, shape, and variability.
3. c. Based on the histogram from Part (a), would it be appropriate to use the Empirical Rule to make statements about the travel time distribution? Explain why or why not.