Errata for 2nd Edition, Fourth Print

 Page/Section

 Chapter 3, Section on Zero Counts (last sentence), p.54

 Correction 

 "...positive errors (under-forecasts) than negative errors (over-forecasts)"

 Page/Section

 Chapter 6, Figure 6.5 (Moving Average Smoothing)

 Correction 

 MAPE should be 212.09

 Page/Section

 Chapter 6, Figure 6.7 (Exponential Smoothing) and page 127 (Section 6.4; "Choosing Smoothing Constant alpha") last paragraph.

 Correction 

 Corrected Figure (uses residuals until Mar-03 to generate forecast of Apr-03 residual) - click to enlarge.

Accordingly, the text should read: "We see that the forecast for the residual is -58,220 riders, implying that we should adjust the regression's forecast by reducing 58,220 riders from that forecast."