The following summarized data (amounts in millions) are taken from the September 30, 2017, and September 24, 2016, comparative financial statements of Apple Inc., a company that designs, manufactures, and markets mobile communication and media devices and personal computers, sells a variety of related software, services, accessories, networking solutions, and offers third-party digital content and applications: 2017 $ 229, 234 114,048 61,344 $ 48,351 2016 $ 215,639 131,376 60,024 45,687 $ $ Amounts Expressed in Millions) For the Fiscal Years Ended September 30 and September 24, respectively: Net sales Costs of sales Operating income Net income At Year End: Assets Current assets: Cash and cash equivalents Short-term marketable securities Accounts receivable, less allowance of $58 and $53, respectively Inventories Vendor nontrade receivables Other current assets Total current assets Long-term marketable securities Property, plant, and equipment, net Goodwill Acquired intangible assets, net Other assets Total assets Liabilities and Shareholders' Equity Current liabilities: Accounts payable Accrued expenses Deferred revenue Commercial paper Current portion of long-term debt Total current liabilities Deferred revenue-noncurrent Long-term debt Other noncurrent liabilities Total liabilities Shareholders' Equity: Common stock and additional paid-in capital, $0.00001 par value, 12,600,000 shares authorized; 5,126,201 and 5,336,166 shares issued and outstanding, respectively Retained earnings Accumulated other comprehensive income (loss) Total shareholdersequity Total liabilities and shareholders' equity $ 20,289 53,892 17,874 4,855 17,799 13,936 128,645 194,714 33,783 5,717 2,298 10,162 $ 375, 319 20,484 46,671 15,754 2,132 13,545 8,283 106,869 170,430 27,010 5,414 3,206 8,757 $ 321,686 $ $ 49,049 25,744 7,548 11,977 6,496 100,814 2,836 97,207 40, 415 241, 272 37,294 22,027 8,080 8,105 3,500 79,006 2,930 75,427 36,074 193,437 35,867 98,330 (150) 134,047 $ 375,319 31,251 96,364 634 128, 249 $ 321,686 At September 26, 2015, total assets were $290,345 and total shareholders' equity was $119,355. Required: a. Calculate Apple Inc.'s working capital, current ratio, and acid-test ratio at September 30, 2017, and September 24, 2016. b. Calculate Apple's ROE for the years ended September 30, 2017, and September 24, 2016. c. Calculate Apple's ROI, showing margin and turnover, for the years ended September 30, 2017, and September 24, 2016