Max’s Shampoo company makes four kinds of shampoo: rose, lemon, ginger, and tea tree. The demand for the four scents are 234, 156, 233 and 137 kg per hour respectively. The production process can produce any shampoo at the rate of 920 kg per hour, but 2 hours are needed to switch between scents. The process doesn’t produce any shampoo during switchover times. Max’s wants to choose a production schedule that (i) cycles repeatedly through the four scents, (ii) meets the required demand and (iii) minimizes the amount of inventory held. Also, Max needs to buy coconut oil to make his shampoo. He needs 1200 kg of coconut oil per day on average. The supplier charges a CHF 88 delivery fee per order (which is independent of the order size) plus coconut oil price, that is, CHF 5.3 per kg. Max's annual holding cost per kg is 28% of the coconut oil price. Assume 52 weeks per year and 5 days per week. How many kg of lemon shampoo should Max produce before switching over to another scent?