Independent solution

How to solve this Supplemental Savings Deposits question

Setup

Setup

The five beginning-year deposits accumulate to time 5 as an annuity-due accumulated value. The two supplements at the beginnings of years 4 and 5 form a two-payment accumulated annuity-due.

S5=14,000s¨50.08+Xs¨20.08S_5=14{,}000\ddot s_{\overline5|0.08}+X\ddot s_{\overline2|0.08}

Model

Model

Grow the time-5 balance to the time-10 goal.

150,000=(14,000s¨50.08+Xs¨20.08)(1.08)5150{,}000=\left(14{,}000\ddot s_{\overline5|0.08}+X\ddot s_{\overline2|0.08}\right)(1.08)^5

Compute

Compute

The time-5 coefficients are 88703.01 for base deposits and 2.2464 for X.

X=5,958.188X=5{,}958.188

Answer

Answer

Each supplemental deposit is about 5958, choice C.

X5,958(C)\boxed{X\approx5{,}958\quad\text{(C)}}