Philadelphia Company has the following information for March:

Sales	$473,081
The variable cost of goods sold	206,923
Fixed manufacturing costs	76,262
Variable selling and administrative expenses	50,481
Fixed selling and administrating expenses	37,584

Determine the March:

a. Manufacturing margin	$fill in the blank 1
b. Contribution margin	$fill in the blank 2
c. Operating income for Philadelphia Company	$fill in the blank 3