Answer:
4.3883 years
Step-by-step explanation:
The investment horizon to be indifferent between both investments is the number of years it takes for the total investment sum + interest on both investments to be the same. If that value is 'n', then
the value of class A mutual fund at n years =
the value of class C mutual fund after n years =
At the point of indifference, the values of both investments will be the same.
Therefore,
This is the value of n that solves the equation (deduced by interpolation).
Therefore the investment horizon of indifference = 4.3883 years.