"the proper solution" is a correct and usable phrase in written English.
You can use it to refer to a solution that is appropriate or correct for a particular situation: For this problem, we must find the proper solution.
The proper solution is to start over.
Groopman says that the proper solution to misdiagnosis instead lies with individual doctors.
The proper solution is to ensure that nuclear waste is safely stored, protected and monitored on site.
Racial purity was never part of church doctrine, Mr. Kertzer writes, nor was "belief in extermination as the proper solution to the 'Jewish Question' " -- indeed that belief, which produced the Holocaust, "went against basic Church doctrine".
He prized facts; he absorbed great quantities of them with ease and was always searching out more, confident that once he had discovered the facts of a problem he could correctly analyze it and then apply the proper solution.
Judge Hurd wrote that the proper solution to actual and perceived conflicts of interest by judges is not to silence them but to require them to recuse themselves from particular cases.
Unfortunately, there are no the proper solutions of the problem (15) on J.
Damljanovic explained the proper solutions and spectrum mobility necessities in cognitive radio networks [16].
The existence of the proper solutions of the perturbed differential Riccati equations ensures stabilizability and detectability of the control system.
Reasoning on this knowledge base by virtue of JESS (Java Expert Shell System) rule engine, maintenance personnel can find the causes of faults of a wind turbine quickly, and choose the proper solutions.
It does seem that our civil discourse has become less civil and more coarse, to the point where, not only can't we agree on the proper solutions, we often can't even agree what the problems are.
