Use the commission schedule from Company B shown in the Principal (Value of Stock) Commission table to find the annual rate of interest earned on the Under $3,000 $32 +1.8% of principal investment. (Note: commisions are rounded to the nearest cent.) $3,000 - $10,000 $56 +1.% of principal Over $10,000 $106 +0.5% of principal An investor purchases 123 shares at $38.28 a share, holds the stock for 336 days, and then sells the stock for $49.77 a share. Assume a 360-day year. The annual rate of interest is %. (Round to three decimal places.)