Mechta;Sorry, but you have to explain more specifically what question you have. Your OP question was about rpm variation "for a given throttle setting", and Turbine D and I replied to that question. If you are asking about rpm's for the maximum thrust available within a given thrust rating (e.g. Max CLB), that's another story. If you are talking about rpm's for the same thrust (e.g. EPR) at various temperatures at a given altitude, that's yet another story.
regards,
HN39
P.S. For a given thrust, altitude and Mach, rpm's of all spools vary in direct proportion to square root of ambient temperature (absolute, e.g. Kelvin). For given ambient temperature, rpm and Mach, thrust varies proportional to ambient pressure.