A Restaurant Has Tracked the Number of Meals Served at Lunch

A restaurant has tracked the number of meals served at lunch over the last four weeks. The data shows little in terms of trends, but does display substantial variation by day of the week. Use the following information to determine the seasonal (daily) index for this restaurant.
$$\begin{array} { | l | l | l | l | l | } \hline & { \text { Week } } \\\hline \text { Day } & 1 & 2 & 3 & 4 \\\hline \text { Sunday } & 40 & 35 & 39 & 43 \\\hline \text { Monday } & 54 & 55 & 51 & 59 \\\hline \text { Tuesday } & 61 & 60 & 65 & 64 \\\hline \text { Wednesday } & 72 & 77 & 78 & 69 \\\hline \text { Thursday } & 89 & 80 & 81 & 79 \\\hline \text { Friday } & 91 & 90 & 99 & 95 \\\hline \text { Saturday } & 80 & 82 & 81 & 83 \\\hline\end{array}$$