A 4½ digit display means:
- 4 full digits + 1 half digit (can show 0 or 1)
- For a 10 V range, it can show values from 0.0000 to 9.9999 (or up to 19.999 in special cases)
So, 0.6794 V is well within the range and is displayed exactly as:
\[
\boxed{0.6794 \ \text{V}}
\]