Computation of Geometric Average Return of a Stock:

Geometric Average Return = { (1 + r₁) * (1 + r₂) * .............( 1 + r_n) } ^1/n - 1

Here,

n = Number of periods or years

r = Rate of return on stock

As per the information given n the question we have n =5;

r₁ = 18 %  ; r₂ = -30 % ;  r₃ = 44% ;  r₄ = -13%   r₅ = 28%

Geometric Average Return = { ( 1 + 0.18) * ( 1 - 0.30 ) * ( 1 + 0.44 ) * ( 1 - 0.13 ) * (1 + 0.28 ) } ^1/5 - 1

= ( 1.18 * 0.70 * 1.44 * 0.87 * 1.28 ) ^1/5 - 1

=( 1.32456 )^1/5 - 1

= 1.0578 - 1

Geometric Average Return = 0.0578 or 5.78%