$\backslash$table$[[$Month$,2011,2012,2013],[$Janury$,438,444,450],[$Fabruary$,420,425,438],[$March$,414,423,434],[$Apnil$,318,331,338],[$May$,306,318,331],[$June$,240,245,254],[$July$,240,255,264],[$August$,216,223,231],[$September$,198,210,224],[$October$,225,233,243],[$November$,270,278,289],[$December$,315,322,335]]$do the following $1)$ compute Centered Moving Average $($because has a trend.... note: must know for exam$)$ and seasonal ratios $($note: each month is a season ie like a quarter, so $12$ seasons$)$; $2)$ Compute seasonal indices for each month, and $3)$ write a paragraph analyzing the results in the case story context $($again$,$ if you need more hand$/$paper practice to prepare for the exam, feel free to do as well$).$