The phrase "a fixed proportion of" is correct and usable in written English.
It can be used when discussing a specific, unchanging ratio or fraction of a whole in various contexts, such as mathematics, finance, or science.
Example: "The recipe requires a fixed proportion of flour to sugar to ensure the right texture."
Alternatives: "a constant ratio of" or "a set percentage of".
Each enzyme recognizes fixed restriction sites and produces fixed restriction tags; thus, it targets a fixed proportion of the deletions.
Mozambique also received a fixed proportion of the Transvaal's railway traffic.
Any union proposition to conference would require not just simple majority support of delegates but support of a fixed proportion of both unions and constituencies.
The MPs had proposed a statutory code to free up local government from Whitehall and proposed that councils are handed a fixed proportion of income tax.
If private schools were willing to take a fixed proportion of low-income pupils, at random, they would be fairly sharing the burdens of the school system.
The key to it is the assumption that consumers tend to spend a fixed proportion of any increases they receive in their incomes.
A few small European corporations already distribute a fixed proportion of after-tax profits to the workforce, and these payments become a very tangible expression of members' rights.
We show using numerical analysis that these schemes converge to a fixed proportion of the full information optimal as the number of peers in the network becomes large.
We show that for a fixed proportion of OD trajectories, the increase in the proportion of fixed detection points increases the accuracy of NFD estimation as expected.
Commenting on his government's opposition to moves to earmark a fixed proportion of seats in parliament for women: "We very much like [having] women in parliament - especially beautiful ones".
Not enough is being done to enforce the laws which order each town to provide a fixed proportion of social housing.
