a$.$ Set the objective as minimizing $($Min$)$ the total cost $($cell E$10).$

b$.$ Use the units produced values $($range B$5$:D$5)$ as the changing variable cells.

c$.$ Adjust the number of units produced by each supplier using the following constraints:

$$ Set the total number of virtual assistants produced $($cell E$5)$ as greater than or equal to $11,000,$ DIG Technology's minimum production goal.

$$ Set the total cost $($cell E$10)$ to be less than or equal to $925,000,$ the maximum total cost DIG Technology wants to spend.

$$ Set the total number of virtual assistants produced by a single supplier $($range B$5$:D$5)$ to be less than or equal to $4000$ to balance the production among the suppliers.

$$ Make sure the values in the range B$5$:D$5$ are integers since DIG Technology cannot sell a fraction of a product.