The current value of an S&R futures is $1578.47. You buy 5 futures on the S&R and the contract size is $361. The margin is settled on a monthly basis and the margin is 14% of the notional value. Margin calls are made as soon as the margin is below 68% of the initial margin level. We assume that r = 3% and observe the following futures prices: Month 0 1 2 3 4 Futures Price $1578.47 $1386.14 $1301.64 $1469.44 $1446.61 Find the monthly margin balance (a) at time 0. (b) at time 1. (c) at time 2. (d) at time 3. at time 4