The following information is available for a company's utility cost for operating its machines over the last four months.

 Month                     Machine hours                     Utility cost    

January                   960                                             $ 5,510  

February                 1,860                                          $ 7,020  

March                       2,520                                          $ 8,700    

April                          660                                              $ 4,050        

Using the high-low method, the estimated total fixed cost for utilities.

• $1,560.
• $4,050.
• $6,060.
• $3,480.
• $2,400.