Which of the following statements about annuities are true? Check all that apply. An ordinary annuity of equal time earns less interest than an annuity due. Annuities are structured to provide fixed payments for a fixed period of time. When equal payments are made at the beginning of each period for a certain time period, they are treated as ordinary annuities. When equal payments are made at the beginning of each period for a certain time period, they are treated as an annuity due.