X Company currently buys a part from a supplier for $14.24 per unit but is considering making the part itself next year. This year, they purchased 3,100 units of this part. Estimated costs to make the part are:

Direct materials: Per-Unit: $3.95 Total: $12,245

Direct labor: Per-Unit: 4.91 Total: 15,221

Variable overhead: Per-Unit: 3.10 Total: 9,610

Fixed overhead:Per-Unit: 5.10 Total:15,810

Total: Per-Unit: $17.06 Total: $52,886

a) If X Company will need 3,100 units again next year and continues to buy the part instead of making it, it will save _______

b) X Company is somewhat uncertain how many units of the part it will need next year. How many units would make the company indifferent between continuing to buy the part and making it?