Is the Asteroid Belt in the same plane as Earth and Jupiter or they are in different planes?
This question is similar to: Do the planets, asteroid belt, kuiper belt, and scattered disk lie on the same plane?
The description of that image:
The orbital inclination histogram [above], which is binned in intervals of 0.1°, shows that asteroids are another exception to this rule. The average orbital inclination is about 8.2°.
Between planets (especially Jupiter) perturbing orbits of asteroids and asteroids occasionally hitting each other and breaking apart the asteroid belt isn't stable enough to gather into a planet or even a single plane or type of orbit. To present the orbits differently, this image from Wikipedia shows the grouping of asteroids in similar orbits:
$i_p(^\circ)$ is inclination from the ecliptic in degrees
and the subscript $p$ stands for proper orbital elements (a kind of average over time) which are distinct from current or osculating orbital elements. See https://en.wikipedia.org/wiki/Asteroid_family#Description