$.$ A trader takes a short position of $5$ contracts in the FTSE futures contract at the close

of trade. One contract is for $10$ times the index. The futures contract has a

maintenance margin of $1000$ and initial market of $1500$ per contract. The index

futures price increases from $1175$ to $1185$ over the course of the first trading day

$($close to close$).$ What is the balance in the trader$$s margin account at the end of the

first day?