RockTop Construction expects to pay a $1.10 dividend next year to its common s

RockTop Construction expects to pay a $1.10 dividend next year to its common stock holders. In each following year common stock dividends
will grow at 4%. RockTop pays its preferred shareholders a dividend of $2.25 every year. If common stock sells at $12.57 per share and preferred stock sells at
$23.41 per share what are the required returns on each type of stock? Why might an investor prefer preferred stock? Why might an investor prefer common
stock?

Answer is preferred=9% and common=12.75% so please walk me through this so with formulas and explainations so that I can understand and do it
on a test. Thanks