what is the formula for the present value of an ordinary annuity 
the formula for the present value of an ordinary annuity is 4p pmt 1 1 1 r n rwhere p present value of an annuity streampmt dollar amount of each annuity paymentr interest rate also known as discount rate n number of periods in which payments will be made begin aligned text p text pmt times frac 1 big frac 1 1 r n big r textbf where text p text present value of an annuity stream text pmt text dollar amount of each annuity payment r text interest rate also known as discount rate n text number of periods in which payments will be made end aligned p pmt r1 1 r n1 where p present value of an annuity streampmt dollar amount of each annuity paymentr interest rate also known as discount rate n number of periods in which payments will be made 