9.) You have an investment account that started with $4 comma 000 10 years ago and which now has grown to $8 comma 000. 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 to two decimal places.)

10.) You are thinking of purchasing a house. The house costs $ 400 comma 000. You have $ 57 comma 000 in cash that you can use as a down payment on the house, but you need to borrow the rest of the purchase price. The bank is offering a 30-year mortgage that requires annual payments and has an interest rate of 10 % per year. What will be your annual payment if you sign this mortgage? The annual payment is $____ (Round to the nearest dollar.)