The phrase "a ratio for" is correct and usable in written English.
It can be used when discussing a specific ratio that serves a particular purpose or function in a mathematical or analytical context.
Example: "The study calculated a ratio for the effectiveness of the new treatment compared to the standard one."
Alternatives: "a proportion for" or "a comparison for".
A ratio for average continental crust of about 0.72 has been determined by measuring strontium from clamshells from the major river systems.
We were given film each month according to a ratio: for every picture published, we earned eight frames.
On Wednesday Barclays refused for the first time to give a ratio for investment bankers' compensation on the grounds that the number would be misleading at the half-year because bonuses are determined at year-end.
Then, to correct for the fact that some drugs, like marijuana, generate many more experience reports than others, I expressed the numbers as a ratio: For each positive experience reported for the drug, how many negative experiences are there?
The total number of citations is 11,079, giving a ratio for the "Average Citations per Item" as 15.45 and "H-index" as 52.
The scale of the rewards – including £3m in shares to the new RBS boss Ross McEwan – were announced to the stock exchange as it emerged the European commission is considering a new clampdown on boardroom pay by requiring firms to disclose a ratio for the gap between executive pay and the pay of an average employee.
The notion is that a price-to-rent ratio is like a price-to-earnings ratio for stocks.
a Ratios for spleen, liver, bonemarrow, kidney and lung.
Even in the wake of the Seattle triumph, oma builds only a fifth of what it designs — a typical ratio for an experimental firm.
a Detection ratio for a system of order four, using single- and multi-watermarks.
Ten drops of bleach is a good ratio for a 2 gallon (7.6 L) bucket.
