ZYX Co. analyses its inventory turnover every 28 days. The company has the following information for each day for the period 1 November to 28 November 2016 (all figures exclude GST): Date Details Amount $ 1/11/2016 Opening inventory $14,000 14/11/2016 Purchase inventory $12,000 16/11/2016 Cost of Sales (for sales this day) $18,000 17/11/2016 Cost of Sales (for sales this day) $15,000 19/11/2016 Cost of Sales (for sales this day) $8,000 22/11/2016 Purchase inventory $22,000 25/11/2016 Purchase inventory $10,000 There are no inventory gains/losses. The average inventory for the period is?