Gelb Company currently makes a key part for its main product. Making this part incurs per unit variable costs of $1.60 for direct materials and $1.15 for direct labor. Incremental overhead to make this part is $1.56 per unit. The company can buy the part for $4.54 per unit. (a) Prepare a make or buy analysis of costs for this part. Note: Enter your answers rounded to 2 decimal places. (b) Should Gelb make or buy the