At the corner restaurant, Caf$$ ABC, managers have tracked the number of meals served at lunch over the last four weeks. The data seem to display

substantial variation by day of the week, and so the manager wants to forecast demand and account for seasonality by day. The data from the last $4$ weeks

are shown in the table below.

$($a$)$ Compute the seasonal index for Friday.

$($Give $3$ decimals.$)$

$($b$)$ A forecaster has given a forecast $($without seasonality$)$ for the total demand of lunch meals for Week $5$ at the restaurant to be $560.$ Compute the

seasonal forecast for Friday of Week $5.$

$($Give answer to one decimal.$)$