Robin Corp. provided the following GAAP income statement. The functional income statement for sales of 20,000 pairs of sunglasses (sales px $50 each) is provided below:

Sales $1,000,000

COGS

Variable manufacturing $525,000

Fixed manufacturing 210,000 735,000

Gross profit 265,000

Sell & Adm.

Variable selling/administrative $50,000

Fixed selling/administrative 40,000 90,000

Op. inc. $ 175,000

Prepare a contribution margin income statement including percentages and unit costs for 21,000 units

Assume Robin sold 1,000 more units. By how much would operating income increase?

Assume Robins sales decreased $1,000, how much would operating income decrease