The phrase "a rather large proportion" is correct and usable in written English.
It can be used when discussing a significant part or percentage of a whole in various contexts, such as statistics, research, or general observations.
Example: "A rather large proportion of the participants reported feeling satisfied with the service provided."
Alternatives: "a considerable percentage" or "a significant share".
A trochanteric flip osteotomy was used in a rather large proportion of the cases in this series.
Although the median misclassification indicate a general overestimation of time spent in MVPA, a rather large proportion of the participants underestimated time in MVPA.
In a rather large proportion of patients with RA, the number of patients with missing data (e.g., DAS28) was for some years rather high.
Among the non-significant pairwise genetic distances, a rather large proportion could actually be due to lack of power in significance testing because of small sample sizes.
One obvious limitation of this study is the missing baseline BMD data from a rather large proportion of included RA patients.
A possible selection bias might be present because a rather large proportion of invited schools declined to take part in the study.
A YouGov poll last summer found that barely one voter in four (27%) wanted Trident replaced "with a new and upgraded system"; about the same number (25%) favoured maintaining the current Trident system, without upgrading or renewing it; but a rather larger proportion (36%) supported scrapping Trident in favour of spending the money on conventional defence forces.
This observation is in accordance with Petersen et al., who along with others, have questioned the results from RCTs with rather large proportions of non-participating patients [ 13].
Dr. Spencer Fifield had an internal-medicine practice that consisted of a nice proportion of businessmen and their wives, plus a rather large assortment of what Spencer's colleagues referred to as "Fifield's screwballs".
Which, when you're talking small amounts in the first place, is rather a large proportion of your tip not going where you'd like it to.
