Use the commission schedule from Company A shown in the table to find the annual rate of interest earned on the investment. (Note: commissions are rounded to the nearest cent.)

Principal (Value of Stock) Commission:

-Under $3,000 $25+1.8% of principal

-$3,000 to $10,000 $37+1.4% of principal

-Over $10,000 $107+.7% of principal

An investor purchases 348 shares at $12.18 a share, holds the stock for 47 weeks, and then sells the stock for $21.55 a share. What is the annual rate %?