CR7.2 ● The article “Water Consumption in the Bay Area”

(San Jose Mercury News, January 16, 2010) reported the accompanying values for water consumption (gallons per person per day) for residential customers of 27 San Francisco Bay area water agencies:

49 52 53 59 59 61 69 70 70 73 79 80 85 87 89 90 92 93 93 95 96 97 114 149 208 318 334

a. Use the given water consumption values to construct a boxplot. Describe any interesting features of the boxplot.

Are there any outliers in the data set?

b. Compute the mean and standard deviation for this data set.

c. If the two largest values were deleted from the data set, would the standard deviation of this new data set be larger or smaller than the standard deviation you computed for the entire data set?

d. How do the values of the mean and median of the entire data set compare? Is this consistent with the shape of the boxplot from Part (a)? Explain.