Consider the following Sales and Operations Plan,

$\backslash$table$[[$Production Quantities,,,,,,$],[$Month $1,$Month $2,$Month $3,$Month $4,$Excess C:F$,$Row Tota$],[$Beginning inventory,$500,,,,,500],[$Month $1$ reg time.,$1500,,,,,1500],[$Month $1$ overtime,$200,200,,,,400],[$Month $1$ subcontracting,,,,,$600,600],[$Month $2$ reg time,,$1600,,,,1600],[$Month $2$ overtime,,$400,,,,400],[$Month $2$ subcontracting,,$300,,,300,600],[$Month $3$ reg time,,,$750,,,750],[$Month $3$ overtime,,,$200,,,200],[$Month $3$ subcontracting,,,$550,,50,600],[$Month $4$ reg time,,,,$1600,,1600],[$Month $4$ overtime,,,,$400,,400],[$Month $4$ subcontracting,,,,$100,500,600],[$Column Total,$2200,2500,1500,2100,1450,9750],[$Total Cost,$704800,,,,,]]$

Monthly demand is represented in the "Column Total" row under Month $1,2,3,4$ cells.

Excess Capacity is represented in the "Excess C$"$ cells.

The "Month..." rows represent production activity in a given month to meet demand.

Note: Numeric answer, i$.$e$.$ DO NOT SPELL your answer.

a$)$ In meeting demand for months $1-4,$ how many total units are to be produced in "Month $1$ overtime"?

units