Analyzing changes in unit costs

The costs of materials consumed in producing good units in the Forming Department of Thomas Company were $6,240 and $6,720 for September and October, respectively. The number of equivalent units produced in September and October was 780 tons, and 1,680 tons, respectively. Evaluate the change in the cost of materials between the two months.

Round all answers to the nearest whole cent.

Energy cost per ton, September	$
Energy cost per ton, October	$

The cost of energy has appeared to (increase or decrease ) by ( ) $ per ton between September and October.