not
Based on the fact that Planet A has a greater mean distance from the Sun than Planet B, you can correctly infer that Planet A likely has a longer orbital period than Planet B. This is because planets that are farther from the Sun generally take longer to complete one orbit.
The related adjective is factual. It means pertaining to a fact, or true (actual).
It is a solution. A very dilute solution, as it is almost entirely water, but in actual fact there is no absolutely pure water anywhere in the world -- even double-distilled water will contain some silicon dioxide in solution from the glass or quartz tubing in which it was distilled.
Salt water is a solution, not a colloid suspension. In a solution, the solute particles are dissolved on a molecular level and do not settle out. Colloid suspensions, on the other hand, have larger solute particles that do not dissolve and may eventually settle out.
obedience
Epsom salt does not cause steel to rust. In fact, soaking steel in a solution of water and Epsom salt can actually help prevent rusting by forming a protective barrier on the steel's surface.
To conclude, or deduce, as in, "from the fact that the triangle is equilateral, and the fact that a triangle is isoceles if and only if the base angles are equal, we can infer that it is also equiangular."
Airplane's contrails do not form clouds; they dissipate soon after they are formed.
A nonexample of "infer" would be simply stating a fact without drawing any conclusions. For instance, if someone says, "The sky is blue," they are presenting a direct observation rather than inferring anything from it. In this case, there is no interpretation or deduction being made based on that statement.
it must be very large
it must be very large
It is a waste product of cellular respiration.
not
I would infer that Darwin was looking for truth, and he was willing to look in various places in order to find it.
He was a very smart man.
There was no solution, which is why Rome did in fact fall.