An investor is evaluating the historical performance of an investment fund. The following annual returns are provided to the investor:

Fund Value

Year $0$ $$260$

Year $1286$

Year $2328$

Year $3315$

Year $4310$

Year $5305$

Required:

a$.$ Calculate the investment returns for each year.

b$.$ Compute the arithmetic mean return.

c$.$ Calculate the geometric mean return.