Use the following to answer the next four questions

ne year ago today, Mike bought $1000$ shares of Umbrella stock for $$90/$share on $55\%$ margin. Mike's broker charged a $7\%$ annual interest rate on borrowed funds and set the maintenance margin level at $40\%.$ Today, Mike closed his position when the stock sold for $$\frac{87}{?}$ share.

How much equity did Mike have to place into his account the day he opened it$?$