Skysong Inc. uses a calendar year for financial reporting. The company is authorized to issue 9,640,000 shares of $10 par common stock. At no time has Skysong issued any potentially dilutive securities. Listed below is a summary of Skysong's common stock activities. 1. 2. Number of common shares issued and outstanding at December 31, 2018 Shares issued as a result of a 10% stock dividend on September 30, 2019 Shares issued for cash on March 31, 2020 Number of common shares issued and outstanding at December 31, 2020 A 2-for-1 stock split of Skysong's common stock took place on March 31, 2021 2,140,000 214,000 2,160,000 3. 4,514,000 4. (a) Compute the weighted-average number of common shares used in computing earnings per common share for 2019 on the 2020 comparative income statement. shares