Please assist with below questions I'm struggling with and brief explanations for understanding

InSight Limited imports reading glasses from China for sale in a Southern African country. During the 2021 financial year, the company adhered to the policy of importing 6 000 pairs of reading glasses every month. The actual monthly sales of reading glasses by InSight Limited during the 2021 financial year is depicted in Table 2.1 below. The company paid R5 000 to place an order for the reading glasses and a carrying cost of R2.00 for each pair of reading glasses during 2021. January 2021 Table 2.1: Actual sales data for the reading glasses during 2021 Month Actual Sales (Pairs of reading glasses) January 2021 2 800 February 2021 3 000 March 2021 5 000 April 2021 4 000 May 2021 5 600 June 2021 8 000 July 2021 8 000 August 2021 7 900 September 2021 6 000 October 2021 4 050 November 202 4 900 December 2021 5 550 3.1 Using the actual sales data provided above, determine the economic order quantity (EOQ) of reading glasses for 2021 financial year. (6 marks) 3.2 Using the EOQ model, determine the number of orders for reading glasses placed by InSight Limited during 2021. (3 marks) 3.3 Suppose that the reading glasses arrive at the premises of Insight Limited 7 days after an order has been placed, determine the level at which Insight Limited had to replenish the stock during 2021 (Assume a 350 working days during 2021). (4 marks) 3.4 Determine how much Insight Limited would save by switching from the current ordering policy to the economic order quantity model. (7 marks)