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​0.7% of principal
An investor purchases 118 shares at $12.37 a​ share, holds the stock for 31 ​weeks, and then sells the stock for $19.01 a share.