Olsen Industries has the following information about maintenance costs in the past six months.

Month	Machine Hours	Amount
January	200	$ 2,800
February	350	3,000
March	450	4,000
April	500	5,000
May	600	5,200
June	580	5,800

Olsens monthly fixed maintenance fee is:

Multiple Choice

$1,600.

$1,200.

$3,600.

$112.

none of the answers is correct.