The smoother the flow between action and thought, the stronger the scene will be.
Although some scenes (and some writers) naturally find the perfect balance between action and internal thought, other scenes take work to get that balance right. Tip it too far in either direction, and the writing can come across as too slow (too much in a character's head) or too flat (all description, no character).
There's no rule or ratio for this, since a writer's voice grows from how they string words together. If we all wrote the exact same way, all books would sound alike. And who wants that?