Travis Metals heats copper ingots to a high temperature by placing them in a large oven. The heated ingots are then run through a shaping machine that forms them into wire. Due to the length of time it takes the oven to heat up$,$ it is never turned off. When the ingots are placed in the oven the temperature is raised to a higher level. Once they are done being heated the oven temperature is turned back down until a new batch of ingots is ready to be heated. The following information shows the ingots processed and the power costs over the past $10$ months.

$\backslash$table$[[$Month$,$Ingots,Power Cost$],[$January$,138,$$$6,620$