Elm Company uses the high-low method of estimating costs. Elm had total costs of 5204,100 at its lowest level of activity; when 12,400 units were sold. When, at its highest level of activity, sales equaled 18,400 units, total costs were $392,200. Elm would estimate variabie cost pee unit as: Multiple Choice $2132 $19.36 $3135 $16.46