The phrase "a sizeable group of" is correct and usable in written English.
It can be used to describe a large number of people or things within a specific context, often in discussions about demographics, research, or social issues.
Example: "A sizeable group of participants expressed their concerns during the meeting."
Alternatives: "a significant number of" or "a large portion of".
"I suspect Stylist will attract quite a sizeable group of people who do not buy into women's weekly magazines".
He fears that The Hum will soon pervade the entire globe and inflict misery on a sizeable group of people.
He is now pinning his hopes on further education - as are a sizeable group of former store managers and sales assistants.
"That's massive nonsense," said David Hussey, one of a sizeable group of Australian Twenty20 players who will not be involved in the Ashes.
"The headteacher and senior leadership team have not identified concerns among a sizeable group of staff that some cultural traditions and beliefs are being promoted more than others".
For a start, there is a sizeable group of European believers with strong social and political views rooted in their faith: Muslims.
Cern bolted the doors to the auditorium hosting the talks from the Atlas and CMS teams, lest any sizeable group of scientists camped out overnight in the lecture theatre.
The non-significant P-values for H d for the mean, mean50 and floormean statistics deny any sizeable group of genes changing in the opposite direction.
Captain Sean O'Loughlin and fellow England international Josh Charnley are among a sizeable group currently out of action.
Ridwan Kamil, the mayor of West Java's capital Bandung, also weighed in on the controversy telling his 2.5 million constituents including a likely sizeable group of LGBT citizens that while he supports the rights of LGBT to exist, they should be neither seen nor heard.
We examined both baseline and radiation-induced DNA damage in PBMCs from a much sizeable group of 50 unselected BC patients compared to that studied before (Djuzenova et al, 1999).
