The Table Below Shows the Number of Pizzas Sold Daily

question 108

Essay

The table below shows the number of pizzas sold daily during a four-week period at King Pizza in Melbourne. $$\begin{array}{l}\quad\quad\quad\quad\quad\quad\quad\quad\text { Week }\\\begin{array} { | l | r r r c | } \hline\text { Day } & 1 & 2 & 3 & 4 \\\hline\text { Sunday } & 253 & 234 & 248 & 232 \\\text { Monday } & 98 & 93 & 99 & 104 \\\text { Tuesday } & 106 & 88 & 87 & 115 \\\text { Wednesday } & 119 & 134 & 113 & 102 \\\text { Thursday } & 138 & 123 & 130 & 118 \\\text { Friday } & 201 & 215 & 218 & 205 \\\text { Saturday } & 327 & 399 & 415 & 390 \\\hline\end{array}\end{array}$$ a. Calculate the seasonal (daily) indexes, using a seven-day moving average.
b. Use regression analysis to find the linear trend line.
c. Calculate the seasonal (daily) indexes, using the trend line developed in (b).