Photo Equipment Store Earnings
the Quarterly Earnings of a Chain

Photo Equipment Store Earnings
The quarterly earnings of a chain of Photo Equipment stores have been recorded for the years 2011-2014.These data (in millions of dollars)are shown in the accompanying table.
$$\begin{array}{l}\text { Year }\\\begin{array} { | c | c c c c | } \hline \text { Quarter } & 2011 & 2012 & 2013 & 2014 \\\hline 1 & 65 & 70 & 73 & 79 \\2 & 80 & 88 & 90 & 95 \\3 & 98 & 103 & 107 & 111 \\4 & 67 & 74 & 76 & 80 \\\hline\end{array}\end{array}$$
-The trend line $\tilde { y } _ { t }$ = 1800 + 75t - 2t² and seasonal indexes shown in the table below were computed from five years of quarterly observations.Forecast the four quarterly values for next year.
$$\begin{array} { | c | c | } \hline \text { Quarter } & \mathbf { SI } _ { \mathbf { t } } \\\hline 1 & 0.575 \\2 & 0.825 \\3 & 1.225 \\4 & 1.375 \\\hline\end{array}$$