Ajax uses the high-low method of estimating costs. Ajax had total costs of $46,940 at its lowest level of activity, when 5,900 units were sold. When, at its highest level of activity, sales equaled 20,700 units, total costs were $79,500. Ajax would estimate fixed costs as:Ajax uses the high-low method of estimating costs. Ajax had total costs of $46,940 at its lowest level of activity, when 5,900 units were sold. When, at its highest level of activity, sales equaled 20,700 units, total costs were $79,500. Ajax would estimate fixed costs as: