Proration rhymes with:
administration, arbitration, calibration, castration, celebration, concentration, conflagration, consecration, dehydration, demonstration, desecration, disintegration, duration, emigration, filtration, frustration, gyration, hydration, illustration, immigration, infiltration, integration, libration, migration, ministration, narration, nitration, oration, orchestration, penetration, prostration, registration, rehydration, sequestration, vibration
Proration sounds like:
paradyne, parden, pardini, pardon, part-time, partain, parten, parthenia, parthenon, parthian, partin, partition, partney, parton, parttime, partum, pepperdine, perdomo, perrodin, pertain, pertamina, portadown, portion, portman, portney, portnoy, predation, predawn, preordain, preteen, prettyman, protean, protein, protium, proton, pruden, prudhomme, purdham, purdin, purdom, purdon, purdum, puritan