Below is the data for a cost$-$benefit problem for Eleko company. $1,2,3,$ and $4$ are different activities the company can undertake. X$,$ Y$,$ and Z are benefits the company gets from the activities.

Benefit Benefit Contribution per Unit of Each Activity Minimum Acceptable Level

$1234$

X $214380$

Y $141360$

Z $3541110$

Unit cost $$500$ $$700$ $$600$ $$400$

Formulate and solve a linear programming model for this problem using Excel.

$1)$ What is the formula you used for the objective function cell? $(1)$

$2)$ How many constraints do you have in your model? Explain. $(1)$

$3)$ How many of units of activity $1,2,3,$ and $4$ should be undertaken? $(1)$

$2)$ What is the total cost? $(1)$