The phrase "a marked number" is correct and usable in written English.
It can be used to refer to a number that has been highlighted, indicated, or noted for a specific reason, often in contexts like mathematics, statistics, or data analysis.
Example: "In the survey results, a marked number of participants indicated a preference for online learning."
Alternatives: "a significant number" or "an indicated number".
The bone marrow was hypercellular due to a marked number of plasma cells.
We noted a marked number of cells staining in the dorsal striatum of WT but not the D1R KO mice.
Arrows indicate a marked number of radially aligned collagen fibers oriented perpendicularly to the tumor-stroma boundary).
A marked number of FM1-43FX-positive cells (21.3±1.6%) were identified in EB growths cultured with ST2-CM.
Kaplan-Meyer analysis for persistence showed that after one year a marked number of patients had discontinued treatment.
However, in a marked number of patients, muraglitazar causes fluid retention that has the potential to lead to congestive heart failure (Buse et al. 2005).
In addition to the positive correlation with household size (as for children and adolescents), there was a marked increased number of more intimate contacts for adults living in Flanders and the Walloon region as opposed to the Brussels region.
Therefore there exist distinct numbers (nu_{1},nu_{2}I}mandfrak_{}) and (k_{0}in[1,rho]) such that (k_{0}) is a (nu_{1} -marked number and (nu_{2})-marked number.
Hynd said that Jeffreys Bay was known as a shark hot-spot but that there had been a marked increase in numbers over the years.
Many species native to Britain are in sharp decline, but the swivel-eyed loon (Gavia articulata oculos) has recently seen a marked increase in numbers, although the rise in sightings could simply be down to better reporting.
After the GM cotton was introduced, researchers saw a marked increase in numbers of pest predators such as ladybirds, lacewings and spiders.
