Apple Inc. is planning to introduce a new product line, and the company expects to sell 1,000 units in the first quarter. Calculate the following:

Item	Amount ($)
Total cost of production	$900,000
Projected revenue	$1,200,000
Gross profit margin	$300,000

Requirement: Determine the gross profit margin when the total cost of production is $900,000 and projected revenue is $1,200,000.