Weyman Z. Wannamaker is the chief financial officer of Cogburn Company. He prides himself on being able to manage the companys cash resources to minimize the interest expense. Consequently, on the second business day of each month, Weyman pays down or draws cash on Cogburns revolving line of credit at First National Bank in accordance with his cash requirements forecast. You are the auditor. You find the information on this line of credit in the following table. You inquired at First National Bank and learned that Cogburn Companys loan agreement specifies payment on the first day of each month for the interest due on the previous months outstanding balance at the rate of prime plus 1.5 percent. The bank gave you a report that showed the prime rate of interest was 8.5 percent for the first six months of the year and 8.0 percent for the last six months. Cogburn Company Notes Payable Balances Date Balance Jan 1 $150,000 Feb 1 200,000 Apr 1 225,000 May 1 285,000 Jun 1 375,000 Aug 1 430,000 Sep 1 290,000 Oct 1 210,000 Nov 1 172,000 Dec 1 95,000 Required: a. Determine an audit estimate of the amount of interest expense you expect to find as the balance of the interest expense account related to these notes payable.