
Chapter 16
PB
Time Series and Index Numbers
659
Figures 16.34, 16.35, and 16.36 are the regression outputs for Example 16.5 using MS Excel,
Minitab and SPSS, respectively. Figure 16.37 is the tted line plot for Example 16.5 produced
using Minitab.
From the Figures 16.34, 16.35, 16.36, and 16.37, it can be seen that the linear trend forecast-
ing equation can be mentioned as below:
Sales = 884.8 + 29.81 (Time period)
The estimated sales 2011 can be obtained by substituting x = 20, that is, time period = 20 in the
above linear trend forecasting equation. So, the estimated sales for 2011 is
Sales = 884.8 + 29.81(20) = `1481 million
The y intercept ...