Hartman, Inc. has prepared the following comparative balance sheets for 2017 and 2018: 2018 2017 Cash Accounts receivable Inventory Prepaid expenses Plant assets Accumulated depreciation Patents s300,760 $157,590 120,510 185,400 27,810 1,313,250 1,081,500 153,470 154,500 18,540 (463,500) (386,250) 157,590 179,220 $1,634,610 $1,365,780 157,590 173,040 43,260 463,500 Accounts payable Accrued liabilities Martgage payable Preferred stock Additional paid-in capital-preferred123,600 Common stock Retained earnings 61,800 540,750 618,000 67,980 $1,634,610 $1,365,780 618,000 132,870