Can someone explain how step 4 is done? I get $20,912,320 but don't understand profit and returns.

Speculating on Anticipated Exchange Rates Chicago Bank expects the exchange rate of the New Zealand dollar to appreciate from its present level of $0.50 to $0.52 in 30 days. Borrows at 7.20% (Annual) for 30 1. Borrows days $20 million 4. Holds $20,912,320 Returns $20,120,000 Profit of $792,320 Exchange at Exchange at $0.50/NZ$ $0.52/NZ$ Lends at 6.48% 2. Holds (Annual) for 30 3. Receives NZ$40 million uays NZ$40,216,000 Exchange at profit of 9 2.000 Speculating on Anticipated Exchange Rates Chicago Bank expects the exchange rate of the New Zealand dollar to appreciate from its present level of $0.50 to $0.52 in 30 days. Borrows at 7.20% (Annual) for 30 1. Borrows days $20 million 4. Holds $20,912,320 Returns $20,120,000 Profit of $792,320 Exchange at Exchange at $0.50/NZ$ $0.52/NZ$ Lends at 6.48% 2. Holds (Annual) for 30 3. Receives NZ$40 million uays NZ$40,216,000 Exchange at profit of 9 2.000