Final answer:
The question relates to the money multiplier effect in a multi-bank system, where an initial excess reserve leads to a multiplying expansion of the money supply through repeated cycles of lending and deposits across various banks.
Step-by-step explanation:
The scenario you've described is an example of how the money multiplier operates within a multi-bank system. When Singleton Bank lends out its excess reserves, it begins a process where money is repeatedly loaned out and deposited at various banks. With each new deposit and subsequent loan, the money supply expands. For instance, Singleton Bank lends $9 million, which becomes a deposit at First National Bank, increasing its reserves by the same amount. First National is then required to keep 10% as required reserves, in this case, $900,000, but can lend out the remaining 90% or $8.1 million. This process continues across different banks, greatly expanding the total money supply in the economy due to the initial loan being re-deposited and re-loaned multiple times.