The Consumer Price Index from 1961 through 2007 is in file XR18085, with 1982–1984 5 100 and 1961 coded as t 5 1. Construct a first-order autoregressive forecasting equation for these data, calculate the mean absolute deviation (MAD) for the fit of the forecast values to the actual values, then use the equation to forecast the CPI for 2008. Source: The New York Times Almanac 2009, p. 338; and Bureau of the Census, Statistical Abstract of the United States 1999, p. 495.