Can someone help me understand how they got the Account M-t-m and the balance?

A September futures contract for 5,000 bu of corn is priced at 244.75 (e per bu). Based on this infonnation calculate the following: b) If an investor purchases (goes long) 2 contracts, how much will s/he need in a margin account to establish a 5% initial margin? 5,000 x 2.4475 x .05 x 2 = Sl,223.75 Suppose the settle price of the contract on the 4 trading days after the contract was made are 242, 239.50, 240.25, and 244 respectively. What is the balance in the margin account at the end of each of these 4 days (ignore margin calls if any)? Price 242 239.5 240.25 244 Account M-t-m -S275 -S2S0 +S75 +S375 Balance S948.75 S698.75 S773.75 Sl,148.75