15-18: Comparing Variations. Consider the following data sets. a. Find the mean, median, and range for each of the two data sets. b. Give the five-number summary and draw a boxplot for each of the data sets. c. Find the standard deviation for each of the data sets. d. Apply the range rule of thumb to estimate the standard deviation of each of the data sets. How well does the rule work in each case? Briefly discuss why it does or does not work well. e. Based on all your results, compare and discuss the two data sets in terms of their center and variation.

15. The table below gives the 2016 Cost of Living Index (COLI) for six cities with a relatively high cost of living and six cities with a relatively low cost of living. The index is based on housing, utilities, grocery items, transportation, health care, and miscellaneous goods and services; 100 represents the national average. High-cost cities Low-cost cities Manhattan, NY 228 Memphis, TN 83 San Francisco, CA 177 Tupelo, MS 83 Washington DC 149 Ashland, OH 82 Oakland, CA 149 Kalamazoo, MI 80 Boston, MA 148 Richmond, IN 80 Seattle, WA 145 McAllen, TX 76 Source: Council for Community and Economic Research