Answer
Denise needs to make a monthly payment of approximately \$256.34 to reach her retirement goal of \$1.2 million in 40 years at a 9% annual interest rate.
Solution
To determine the monthly payment Denise needs to make to reach her retirement goal of \$1.2 million in 40 years at an annual interest rate of 9%, we can use the future value of an annuity formula:
\[
FV = P \times \frac{(1 + r)^n - 1}{r}
\]
Where:
- \( FV \) is the future value of the annuity (the retirement goal, \$1,200,000).
- \( P \) is the monthly payment (what we want to find).
- \( r \) is the monthly interest rate (annual rate divided by 12).
- \( n \) is the total number of payments (number of years multiplied by 12).
### Step 1: Calculate the monthly interest rate and total number of payments
- Annual interest rate \( = 9\% = 0.09 \)
- Monthly interest rate \( r = \frac{0.09}{12} \)
- Total number of payments \( n = 40 \times 12 \)
### Step 2: Substitute the values into the formula and solve for \( P \)
Rearranging the formula to solve for \( P \):
\[
P = \frac{FV \times r}{(1 + r)^n - 1}
\]
Now, let's calculate the values step by step.
1. Calculate \( r \) and \( n \):
- \( r = \frac{0.09}{12} \)
- \( n = 40 \times 12 \)
2. Substitute \( FV = 1,200,000 \), \( r \), and \( n \) into the formula for \( P \).
Let's perform these calculations.
Calculate the value by following steps:
- step0: Calculate:
\(40\times 12\)
- step1: Multiply the numbers:
\(480\)
Calculate or simplify the expression \( 0.09/12 \).
Calculate the value by following steps:
- step0: Calculate:
\(\frac{0.09}{12}\)
- step1: Convert the expressions:
\(\frac{\frac{9}{100}}{12}\)
- step2: Multiply by the reciprocal:
\(\frac{9}{100}\times \frac{1}{12}\)
- step3: Reduce the numbers:
\(\frac{3}{100}\times \frac{1}{4}\)
- step4: Multiply the fractions:
\(\frac{3}{100\times 4}\)
- step5: Multiply:
\(\frac{3}{400}\)
Calculate or simplify the expression \( 1200000*(0.0075)*((1+0.0075)^480-1) \).
Calculate the value by following steps:
- step0: Calculate:
\(1200000\times 0.0075\left(\left(1+0.0075\right)^{480}-1\right)\)
- step1: Add the numbers:
\(1200000\times 0.0075\left(1.0075^{480}-1\right)\)
- step2: Convert the expressions:
\(1200000\times 0.0075\left(\left(\frac{403}{400}\right)^{480}-1\right)\)
- step3: Subtract the numbers:
\(1200000\times 0.0075\times \frac{403^{480}-400^{480}}{400^{480}}\)
- step4: Multiply the terms:
\(9000\times \frac{403^{480}-400^{480}}{400^{480}}\)
- step5: Rewrite the expression:
\(200\times 45\times \frac{403^{480}-400^{480}}{400^{480}}\)
- step6: Rewrite the expression:
\(200\times 45\times \frac{403^{480}-400^{480}}{200^{480}\times 2^{480}}\)
- step7: Reduce the numbers:
\(45\times \frac{403^{480}-400^{480}}{200^{479}\times 2^{480}}\)
- step8: Rewrite the expression:
\(5\times 9\times \frac{403^{480}-400^{480}}{200^{479}\times 2^{480}}\)
- step9: Rewrite the expression:
\(5\times 9\times \frac{403^{480}-400^{480}}{25^{479}\times 8^{479}\times 2^{480}}\)
- step10: Rewrite the expression:
\(5\times 9\times \frac{403^{480}-400^{480}}{5^{958}\times 8^{479}\times 2^{480}}\)
- step11: Reduce the numbers:
\(9\times \frac{403^{480}-400^{480}}{5^{957}\times 8^{479}\times 2^{480}}\)
- step12: Multiply the fractions:
\(\frac{9\left(403^{480}-400^{480}\right)}{5^{957}\times 2^{1917}}\)
- step13: Multiply:
\(\frac{9\times 403^{480}-9\times 400^{480}}{5^{957}\times 2^{1917}}\)
Calculate or simplify the expression \( (1+0.0075)^480-1 \).
Calculate the value by following steps:
- step0: Calculate:
\(\left(1+0.0075\right)^{480}-1\)
- step1: Add the numbers:
\(1.0075^{480}-1\)
- step2: Convert the expressions:
\(\left(\frac{403}{400}\right)^{480}-1\)
- step3: Rewrite the expression:
\(\frac{403^{480}}{400^{480}}-1\)
- step4: Reduce fractions to a common denominator:
\(\frac{403^{480}}{400^{480}}-\frac{400^{480}}{400^{480}}\)
- step5: Transform the expression:
\(\frac{403^{480}-400^{480}}{400^{480}}\)
Calculate or simplify the expression \( 1200000*0.0075/35.109902 \).
Calculate the value by following steps:
- step0: Calculate:
\(\frac{1200000\times 0.0075}{35.109902}\)
- step1: Multiply the numbers:
\(\frac{9000}{35.109902}\)
- step2: Convert the expressions:
\(\frac{9000}{\frac{17554951}{500000}}\)
- step3: Multiply by the reciprocal:
\(9000\times \frac{500000}{17554951}\)
- step4: Multiply:
\(\frac{9000\times 500000}{17554951}\)
- step5: Multiply:
\(\frac{4500000000}{17554951}\)
### Step 1: Calculate Monthly Interest Rate and Total Payments
- Monthly interest rate \( r = 0.0075 \)
- Total number of payments \( n = 480 \)
### Step 2: Substitute Values into the Formula
We need to calculate the monthly payment \( P \) using the rearranged formula:
\[
P = \frac{FV \times r}{(1 + r)^n - 1}
\]
Substituting the values:
- \( FV = 1,200,000 \)
- \( r = 0.0075 \)
- \( n = 480 \)
Calculating \( (1 + r)^n - 1 \):
\[
(1 + 0.0075)^{480} - 1 \approx 35.109902
\]
Now substituting into the formula for \( P \):
\[
P = \frac{1,200,000 \times 0.0075}{35.109902} \approx 256.34
\]
### Final Answer
Denise needs to make a monthly payment of approximately **\$256.34** to reach her retirement goal of \$1.2 million in 40 years at a 9% annual interest rate.
Reviewed and approved by the UpStudy tutoring team
Explain
Simplify this solution