Tobit bought $3,706 worth of stock on margin with an initial margin requirement of 62%. A change in the stock price caused the margin to increase to 78%. By how much did Tobin's ROE exceed ROA?

Raphael bought $6,575 worth of stock on margin. The initial margin was 66% and the maintenance margin was 22%. Unfortunately, actual margin decreased to 18%. Raphael deposited enough cash to raise the margin to 35%.

Round all 4 decimal places

forgot on the 2nd question, how much cash did raphael deposit?