When Sandra Costello s father died suddenly, Sandra had just completed the semester in college, so she stepped in to run the family business, Costello s Delivery Service, until it could be sold. Under her father s direction, the company was a successful operation and provided ample money to meet the family s needs. Sandra was majoring in biology in college and knew little about business or accounting, but she was eager to do a good job of running the business so it would command a good selling price. Since all of the services performed were paid in cash, Sandra figured that she would do all right as long as the Cash account increased. Thus, she was delighted to watch the cash balance increase from $25,000 at the beginning of the first month to $73,028 at the end of the second month-an increase of $48,028 during the two months she had been in charge. When she was presented an income statement for the two months by the company s bookkeeper, she could not understand why it did not show that amount as income but instead reported only $ 19,100 as net income. Knowing that you are taking an accounting class, Sandra brings the income statement, shown below, to you and asks if you can help her understand the difference. In addition, Sandra permits you to examine the accounting records, which show that the balance of Salaries Payable was $12,680 at the beginning of the first month but had increased to $25,040 at the end of the second month. Most of the balance in the Insurance Ex