base period market basket of goods and services in the CPI has risen from $10 in 1982-84 to $11.65. For further details visit the CPI home page on the Internet at http://www.bls.gov/cpi/ or contact our CPI Information and Analysis Section on (202) 691-7000. Note on Sampling Error in the Consumer Price Index The CPI is a statistical estimate that is subject to sampling error because it is based upon a sample of retail prices and not the complete universe of all prices. BLS calculates and publishes estimates of the 1-month, 2-month, 6-month and 12-month percent change standard errors annually, for the CPI-U. These standard error estimates can be used to construct confidence intervals for hypothesis testing. For example, the estimated standard error of the 1 month percent change is 0.03 percent for the U.S. All Items Consumer Price Index. This means that if we repeatedly sample from the universe of all retail prices using the same methodology, and estimate a percentage change for each sample, then 95% of these estimates would be within 0.06 percent of the 1 month percentage change based on all retail prices. For example, for a 1-month change of 0.2 percent in the All Items CPI for All Urban Consumers, we are 95 percent confident that the actual percent change based on all retail prices would fall between 0.14 and 0.26 percent. For the latest data, including information on how to use the estimates of standard error, see "Variance Estimates for Price Changes in the Consumer