Directions for Comparing VariabilityIn your study of statistics, you have calculated the mean and the standard deviation of many different samples of data. You have learned that the more the data entries are “spread out”, the greater is the standard deviation. As a comparative measure of variation, however, the standard deviation has the disadvantage of being dependent upon units of measure. This makes the comparison of measurements from different populations very difficult. The Coefficient of Variation (or CV) defines the standard deviation as a percent of the mean. Since the CV has no units, direct comparison of the variability of different populations may be made. You will be accessing the United States Department of Labor Bureau of Labor Statistics website http://data.bls.gov and collecting data from the Consumer Price Index (or CPI). Your work will be done on the accompanying worksheet. Getting Started (Fill in the worksheet as you go.)
