This is a reasonable approximation of stock price dynamics except for rare events.
He was old enough that he knew how to create a reasonable approximation of a human.
They decided finally that the code could be considered binary "to a reasonable approximation."
Many might consider this a reasonable approximation of an afterlife.
Then he added, with a chuckle, "The only one here who still has an actual job- or at least a reasonable approximation."
We view this as a main effect and thus a reasonable approximation.
In the absence of such precision, reasonable approximations may be considered.
Given sufficient samples, a reasonable approximation of the value can be achieved.
And then he does the whole thing again until he has a reasonable approximation of the original.
The most we can hope for is a reasonable approximation of the truth.