Step 1: Find frequency range.
\[
f_{min} = 10.5 - 4.5 = 6\,MHz,\quad f_{max} = 10.5 + 4.5 = 15\,MHz
\]
Step 2: Convert to wavelength range.
\[
\lambda = \frac{c}{f}
\]
Step 3: Compute extreme wavelengths.
\[
\lambda_{max} = \frac{3 \times 10^8}{6 \times 10^6} = 50\,m
\]
\[
\lambda_{min} = \frac{3 \times 10^8}{15 \times 10^6} = 20\,m
\]
Step 4: Bandwidth in wavelength.
\[
\Delta \lambda = 50 - 20 = 30\,m
\]
Step 5: Final conclusion.
Thus, wavelength bandwidth is \(30\,m\).
Step 6: Final answer.
\[
\boxed{30\,m}
\]