temperature that corresponds to a specific heat

Mechanical engineers, as well as most other engineers, use thermodynamics extensively in their work. The following polynomial can be used to relate the zero-pressure specific heat of dry air, cp kJ/(kg K), to temperature (K):
cp = 0.99403 + 1.671 × 10−4T + 9.7215 × 10−8T 2
−9.5838 × 10−11T 3 + 1.9520 × 10−14T 4
Determine the temperature that corresponds to a specific heat of 1.2 kJ/(kg K).