I need formulas and explanations)

Alternative dividend policies Over the last 10 years, a firm has had the earnings per share shown in the following table. Earnings per share Year 2012 2011 2010 2009 2008 $4.00 3.80 Year 2007 2006 2005 2004 2003 Earnings per share $2.40 1.20 3.20 1.80 2.80 -0.50 3.20 0.25 a. If the firm's dividend policy were based on a constant payout ratio of 40% for all years with positive earnings and 0% otherwise, what would be the annual divi- dend for each year? b. If the firm had a dividend payout of $1.00 per share, increasing by $0.10 per share whenever the dividend payout fell below 50% for two consecutive years, what annual dividend would the firm pay each year? c. If the firm's policy were to pay $0.50 per share each period except when earnings per share exceed $3.00, when an extra dividend equal to 80% of earnings beyond $3.00 would be paid, what annual dividend would the firm pay each year