The phrase "rough proportion" is correct and usable in written English.
It can be used when discussing an approximate or general relationship between quantities or sizes.
Example: "The budget for the project was allocated in a rough proportion to the expected outcomes."
Alternatives: "approximate ratio" or "general proportion".
People in every occupation go bankrupt in rough proportion to their numbers, they found.
Its benefits rise in rough proportion to the cost of the care they receive.
It has 785 members, directly elected in rough proportion to each country's population.
Ed believed that we are born with two ears and one mouth and we should use them in rough proportion".
The moderate tries to maintain a rough proportion between them, to keep her country along its historic trajectory.
Judge Lance Ito had parcelled out our places in the courtroom in rough proportion to our status in the media world.
In fact, those are the rough proportions by which the 1914 populations were smaller than today's.
In practice, when converting a competitive-type national IO table (an IO table without a separated import matrix) into non-competitive-type IO table (an IO table with a separated import matrix), a useful but sometimes rough "same proportion assumption" is always conducted.
There are no national figures that break down what proportion of rough sleepers are from the UK and from the EU but, in London, 43% of rough sleepers recorded in 2014-15 were from the UK, while 35% were from central and eastern European countries.
Jeremy Paxman: Give as you rough indication of what proportion it might be?
At a 2011 evolutionary biology conference, she noticed that women were significantly underrepresented among speakers, so she went through the abstracts and made a rough estimate of the proportion of men and women.
