please answer this last one part (c)

Grouper Inc. uses a calendar year for financial reporting. The company is authorized to issue 8,680,000 shares of $10 par common stock. At no time has Grouper issued any potentially dilutive securities. Listed below is a summary of Grouper'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 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