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 300,760 157,590 120,510 185,400 27,810 1,313,250 1,081,500 153,470 154,500 18,540 (463,500) (386,250) 57,590 Accounts payable Accrued liabilities Martgage payable Preferred stock 179,220 $1,634,610 $1,365,780 157,590 173,040 43,260 463,500 61,800 540,750 Additional paid-in capital-preferred123,600 618,000 132,870 Common stock 618,000 67,980 $1,634,610 $1,365,780 Retained earnings