Question 4 Snowball Company received beginning inventory of 100 units at a unit cost of $20 each. It engaged in the following purchase and sale transactions during 2020: 14 January Sold 20 units at unit sales price of $45 on open account. 9 April Purchased 15 additional units at unit cost of $20 on open account. 2 September Sold 45 units at sales price of $50 on open account. At the end of 2020, a physical count showed that Snowball Company had 50 units of inventory still on hand. Required: Record each transaction, assuming that Snowball Company uses (a) a perpetual inventory system and (b) a periodic inventory system (including any necessary entries at the end of the accounting period on 31 December)