Monthly usage data for pallets used in a distribution center are as follows:

Month $1234$

January $1,4841,4821,7921,902$

February $1,3941,4001,5861,722$

March $1,5521,5481,7701,876$

April $1,7961,8642,1102,218$

May $2,0602,1982,4082,548$

June $2,2142,4462,6522,844$

July $2,3302,5802,6062,972$

August $2,4322,6982,8723,110$

September $2,4162,6822,9463,208$

October $2,2622,5922,9063,200$

November $1,9422,1322,3402,806$

December $1,5661,8022,0462,418$

Click here for the Excel Data File

Calculate the monthly usage index for each month.

Use simple linear regression to forecast total usage of pallets for year $5.$

Forecast the seasonally adjusted usage for pallets for each month in year $5.$