To find the value of \( A(8) \) using the equation \( A(t) = 6(2)^{0.25t} \), we will substitute \( t = 8 \) into the equation.
\[ A(8) = 6(2)^{0.25 \times 8} \]
Calculating \( 0.25 \times 8 \):
\[ 0.25 \times 8 = 2 \]
Now substitute this back into the equation:
\[ A(8) = 6(2)^{2} \]
Now compute \( (2)^2 \):
\[ (2)^2 = 4 \]
Now substitute that in:
\[ A(8) = 6 \times 4 = 24 \]
Thus, the value for \( A(8) \) is \( \boxed{24} \).