Ron's Tennis Ball Shop sells tennis balls to the general public. Ron uses the Perpetual System to track his Inventory of tennis balls. Below is the completed Inventory Record for tennis balls, for July 2021. PRODUCT: Tennis balls (cost price) DATE IN OUT BALANCE (in shop) of tennis balls 15 @ $2 each 15 @ $2 each 300@ $2.5 each 280 @ $2.5 each 2020 1st July 3rd July 300@ $2.5 each 7th July 15 @ $2 each 20 @ $2.5 each 10th July 400 @ $3 each 280 @ $2.5 each 400 @ $3 each 15th July ? 360 @ $3 each 19th July 300 @ $3 each 60 @ $3 each Requirement 1 Which inventory costing method does Ron use? Explain your answer (1 mark) Requirement 2 What is the Cost of Goods Sold for the 15th July transaction (as indicated by the question mark above)? (2 marks) Requirement 3 Describe the effect that an increase in inventory purchase prices will have on Gross profit and ending inventory values under the FIFO, LIFO and Weighted Average valuation methods (3 marks)