23.3k views
2 votes
The fast-food restaurant manager receives a $5,000 bonus and adds it to the initial investment. The manager wants to see how much less time it would take the retirement fund to grow with the additional $5,000 and continuously compounded interest. The amount of time it would take the manager to reach a balance of $65,000 with continuously compounded interest can be modeled by the equation ln 3.25 = ln e0.0595t. How much less time does it take the new investment to reach the same balance? Solve for the time in years, rounded to the nearest tenth of a year, showing all steps.

1 Answer

2 votes

Answer: To find the time it would take the new investment to reach a balance of $65,000 with continuously compounded interest, we can use the equation:

ln(3.25) = ln(e^(0.0595t)).

First, we need to solve for t. To do that, we can get rid of the natural logarithm on both sides by using the property: ln(e^x) = x.

So, the equation becomes:

3.25 = e^(0.0595t).

Now, let's isolate t:

Take the natural logarithm on both sides:

ln(3.25) = ln(e^(0.0595t)).

Using the property: ln(e^x) = x, we get:

ln(3.25) = 0.0595t.

Now, divide by 0.0595 to solve for t:

t = ln(3.25) / 0.0595.

Let's calculate the value of t:

t = ln(3.25) / 0.0595 ≈ 35.81 years.

So, it would take approximately 35.81 years for the new investment to reach a balance of $65,000 with continuously compounded interest.

Now, let's calculate how much less time it would take with the additional $5,000.

Let's assume the original time it would take to reach $65,000 without the $5,000 bonus is t_1, and the time it would take with the $5,000 bonus is t_2.

t_1 = 35.81 years (from the previous calculation).

The new investment has an additional $5,000, so the future value (FV) of the investment will be $65,000 + $5,000 = $70,000.

Using the same formula as before, we have:

ln(3.25) = ln(e^(0.0595 * t_2)).

Now, solve for t_2:

3.25 = e^(0.0595 * t_2).

Take the natural logarithm on both sides:

ln(3.25) = 0.0595 * t_2.

Now, divide by 0.0595 to solve for t_2:

t_2 = ln(3.25) / 0.0595 ≈ 36.92 years.

So, with the additional $5,000 bonus, it would take approximately 36.92 years to reach a balance of $70,000 with continuously compounded interest.

Now, to find how much less time it would take, we subtract t_1 from t_2:

Time difference = t_2 - t_1 ≈ 36.92 - 35.81 ≈ 1.11 years.

Therefore, the new investment with the $5,000 bonus takes approximately 1.11 years less to reach a balance of $65,000 compared to the original investment.

User Bujar
by
8.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.