Each of the following independent events requires a year-end adjusting entry. Show how each event and its related adjusting entry affect the accounting equation. Assume a December 31 closing date. The first event is recorded as an example. (Do not round intermediate calculations. Enter any decreases to account balances with a minus sign.) a. Paid $6,100 cash in advance on April 1 for a one-year insurance policy. b. Purchased $1,650 of supplies on account. At years end, $110 of supplies remained on hand. c. Paid $6,150 cash in advance on March 1 for a one-year lease on office space. d. Received an $15,150 cash advance for a contract to provide services in the future. The contract required a one-year commitment starting September 1.