Suppose you buy a share of stock for $45. After one year, the value of the stock has risen to $52, and you have received an extra $1.20 in dividends. Find the simple interest rate of growth of this investment. Give your answer as a percentage with one decimal place (you'll need three decimal places when solving for r).

For this problem P = $45 and S = $52 + $1.20 = $53.20.