Final answer:
The nominal annual rate of interest compounded monthly earned by this perpetuity is 6%.
Step-by-step explanation:
To calculate the nominal annual rate of interest compounded monthly earned by this perpetuity, we can use the present value formula. The present value of the perpetuity is given as $4623. The monthly payment is $23. We can use the formula:
PV = C / r
Where PV is the present value, C is the monthly payment, and r is the nominal annual rate of interest compounded monthly. Substituting the given values:
$4623 = $23 / r
Rearranging the equation to solve for r:
r = $23 / $4623 = 0.005 (or 0.5%)
Multiplying by 12 to get the nominal annual rate:
0.005 * 12 = 0.06 (or 6%)
Therefore, the nominal annual rate of interest compounded monthly earned by this perpetuity is 6%.