The specific heat at constant pressure for an ideal gas is given by $C_p=a+bT,(k\frac{J}{k}g*K)$ where $T$ is in kelvin.

a$.$ Calculate the change in the enthalpy for this ideal gas undergoing a process in which the temperature changes from $27$ to $127C.$ Given that: $a=0\mathrm{.}9,$ and $b=2\mathrm{.}7{10}^{-4}.$

b$.$ Repeat the above calculation. given that average $C_p=0\mathrm{.}9.$