The Hard Rock Mining Company wants to separate its utilities cost into variable and foxed elements for planning purposes. The controller belleves tons mined might be a good base for developing a cost formula. The production superintendent disagrees; she thinks direct labor$-$hours would be a better base. Quarterly data for tons mined, direct labor$-$hours, and utilities cost are os follows:

$\backslash$table$[[$Ouarter$,$Tons Mined,$\backslash$table$[[$Direct Labar$-],[$Hours$]],$Utilities cost$],[$Year $1$:$],[$First$,20,0e,5,500,$$$55,088$