Almost half of Ireland's population is under twenty-five, and with its universities and professional schools, Dublin also has a large student population.
Dublin has a large student population due to half of Ireland's population being under 25. 
mnli hypothesis: Dublin has a large student population due to half of Ireland's population being under 25.  premise: Almost half of Ireland's population is under twenty-five, and with its universities and professional schools, Dublin also has a large student population.