Machine Master, Inc. had the following data regarding monthly power costs:

Month	Machine hours	Power cost
Jan	300	$680
Feb	600	720
Mar	400	695
Apr	200	640

1. Assume that management expects 500 machine hours in May. Using the high-low method, calculate Mays power cost using machine hours as the basis for prediction.
   1. 700
   2. 705
   3. 710
   4. 1320