Vaughn Inc. uses a calendar year for financial reporting. The company is authorized to issue 8,810,000 shares of $12 par common stock. At no time has Vaughn issued any potentially dilutive securities. Listed below is a summary of Vaughns common stock activities.

1.		Number of common shares issued and outstanding at December 31, 2018		1,850,000
2.		Shares issued as a result of a 12% stock dividend on September 30, 2019		222,000
3.		Shares issued for cash on March 31, 2020		2,180,000
		Number of common shares issued and outstanding at December 31, 2020		4,252,000
4.		A 2-for-1 stock split of Vaughns common stock took place on March 31, 2021

a) Compute the weighted-average number of common shares used in computing earnings per common share for 2019 on the 2020 comparative income statement.

b) Compute the weighted-average number of common shares used in computing earnings per common share for 2020 on the 2020 comparative income statement.

c) 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.

d) 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.