Ferguson Company has the following information for July:

Sales	$680,000
Variable cost of goods sold	312,800
Fixed manufacturing costs	108,800
Variable selling and administrative expenses	74,800
Fixed selling and administrative expenses	47,600

Determine the following for Ferguson Company for the month of July:

a. Manufacturing margin	$fill in the blank 1
b. Contribution margin	$fill in the blank 2
c. Operating income