$12$

$23$

$($a$)$ Compute four$-$week and five$-$week moving averages for the time series.

Do not round intermediate calculations. If required, round your answers to two decimal places.

$\backslash$table$[[$Week$,$Sales,$\backslash$table$[[4-$Week$],[$Moving$],[$Average$]],\backslash$table$[[5-$Week$],[$Moving$],[$Average$]]],[1,17,,],[2,23,,E$