Step 1: Define B.
Let B equal x. Since A exceeds B by 50%, the equation for A is:
\[
A = x + 0.50x = 1.5x
\]
Step 2: Relate B and C.
B is 25% less than C, which can be expressed as:
\[
B = C - 0.25C = 0.75C
\]
This implies that \( C = \frac{B}{0.75} = \frac{x}{0.75} = \frac{4x}{3} \).
Step 3: Calculate the ratio A to C.
Using the derived values \( A = 1.5x \) and \( C = \frac{4x}{3} \), the ratio \( A : C \) is computed as:
\[
A : C = \frac{1.5x}{\frac{4x}{3}} = \frac{1.5 \times 3}{4} = \frac{4.5}{4} = \frac{9}{8}
\]
Therefore, the ratio \( A : C \) is \( 9 : 8 \).
Final Answer: \[ \boxed{9:8} \]