Find the Final Amount (Rounded to the Nearest Dollar) in This

Multiple Choice

Find the final amount (rounded to the nearest dollar) in this retirement account, in which the rate of return on the account and the regular contribution change over time.
- $\$ 1500$ per quarter invested at $7.9 \%$ , compounded quarterly, for 20 years; then $\$ 1000$ per quarter invested at $6.8 \%$ , compounded quarterly, for 10 years.

A) About $\$ 828,071$
B) About $\$ 343,772$
C) About $\$ 460,646$
D) About $\$ 620,187$