Cardinal uses the high-low method of estimating costs. Cardinal had total costs of $26,450 at its lowest level of activity, when 7,100 units were sold. When, at its highest level of activity, sales equaled 12,700 units, total costs were $39,890. Cardinal would estimate variable cost per unit as: V Multiple Choice O $3.35 $3.73 O $3.14 O $2.40