For the given question, the formula to determine the periodic deposit will be:
![A=\frac{P((1+(r)/(n))^{nt^{}}-1)}{(r)/(n)}](https://img.qammunity.org/2023/formulas/mathematics/college/hoasppia1p3z9wshf8wvb3bxmn4k8872tl.png)
Given:
A= $1,000,000
r = 8.25% = 0.0825
Componded monthly, n = 12
time = t = 40 years
We will substitute with the given values and find the value of P
So,
![\begin{gathered} 1000000=(P\cdot((1+(0.0825)/(12))^(12\cdot40)-1))/((0.0825)/(40)) \\ 1000000=P\cdot12,513.06881 \\ \\ P=(1000000)/(12513.06881)=79.916 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1c3se9w1zlk5styamsubop7nigurk030aj.png)
Rounding to the nearest dollar
so, The periodic deposit = $80
Part (b): we will find the amount comes from the deposit and the amount comes from the interest
The amount of money comes from deposit = 80 * 12 * 40 = $38,400
The amount comes from the interest = 1000000 - 38400 = $961600