You have an investment account that started with ?$3000 10 years ago and which now has grown to ?$6000. a. What annual rate of return have you earned? (you have made no additional contributions to the? account)? b. If the investment account earns 15 % per year from now? on, what will the? account's value be 10 years from? now? a. What annual rate of return have you earned? (you have made no additional contributions to the? account)? Your annual rate of return is_.(round two decimal places)