Final answer:
The accumulated value 16 years after the first payment is made of an annuity with 6 payments of $850 each made at 2-year intervals and an interest rate of 4.1% is $2018.05.
Step-by-step explanation:
To find the accumulated value 16 years after the first payment is made of an annuity, we can use the formula for the future value of an annuity:

Where FV is the accumulated value, P is the payment amount, r is the interest rate per period, and n is the number of periods. In this case, P = $850, r = 4.1% / 6 (since the interest is convertible once every two months), and n = 6 payments * 8 (since there are 8 two-month periods in a year).
Plugging in the values, we get:

Therefore, the accumulated value 16 years after the first payment is made is $2018.05.