The seller of magnetic chip cards provided the following information for the period ending 31 December 2021. Production (Units) Sales (Units) Budgeted Actual 180,000 192,000 174,000 186,000 Budgeted Actual Fixed production cost Fixed selling overhead $1,800,000 $1,350,000 $1,875,000 $1,350,000 The fixed production overhead was absorbed at a pre-determined rate per unit produced. One supplement was sold for $520. At the beginning of January 2021, there was opening inventory of 10,500 units valued at $630,000; this includes fixed production overhead of $105,000. "Hint-enough information is provided to calculate the variable cost per unit.