The investment value in 16 years would be approximately $41,918.59.
Diana receives a $5,000 bonus each year and decides to invest it into an index fund with an annual historical growth rate of 16%. To find the investment value in 16 years, we can use the formula for compound interest:

Where:
A = the amount of money accumulated after n years, including interest.
P = the principal amount (the initial amount of money).
r = the annual interest rate (decimal).
n = the number of years the money is invested.
In this scenario, P is $5,000, r is 0.16 (16% expressed as a decimal), and n is 16 years.
By substituting the values we get:
A =

A =

A ≈ $41,918.59
Therefore, the investment value in 16 years would be approximately $41,918.59.