please help

Lockrite Security Company manufacturers home alarms. Currently, it is manufacturing one of its components at a total cost of $45, which indudes fixed costs of s14 per unit. An outside provider of this component has offered to sell Lockrite the component for $41. Provide a differential analysis of the outside purchase proposal. If an amount is zero, enter " 0 ", For those boxes in which you must enter subtracted or negative numbers use a minus sign