Monty Inc. uses a calendar year for financial reporting. The company is authorized to issue 8,490, 000 shares of $10 par common stock. At no time has Monty issued any potentially dilutive securities. Listed below is a summary of Monty's common stock activities. Compute the weighted- average number of common shares used in computing earnings per common share for 2019 on the 2020 comparative income statement. shares Compute the weighted-average number of common shares used in computing earnings per common share for 2020 on the 2020 comparative income statement. shares Compute the weighted-average number of common shares to be used in computing earnings per common share for 2020 on the 2021 comparative income statement. shares eTextbook and Media Compute the weighted-average number of common shares to be used in computing earnings per common share for 2021 on the 2021 comparative income statement..