pv = nRT
Assuming v, n, R are constant:
P/Po = T/To
p= T/To/Po
P = (49+273) / (72+273)*(14.7+12.5)= 25.4 psia
PSIG = (25.4-14.7) = 10.7
I believe you made the same temperature conversion error in your post #192 that I made in my post #60 (I corrected it in my post #191).
K = (F + 460) * 5/9
Not K = F + 273
You mixed Farenheit with Celsius in your calculation of the temperature change. If you use consistent units, the change is lower (i.e., if you use Kelvin/Celsius, you don’t have 49 and 72— you have (17*5/9) for the 49, and 40*5/9 for the 72. THat is 49 degrees F is (0 +(49-32)*5/9) in the other scale.