You have to use the ideal gas law of PV=nRT.
In this case, you just have to plug in the given variables.
P (pressure) = 4.68 atm
V (volume) = 4.95 L
n (number of moles) = 16.45
R (gas constant) = .0821
T (temperature) is what youre trying to solve so:
(4.68)*(4.95) = (16.45)*(.0821)*T
To get T by itself, divide both sides by (16.45)*(0.821) to get T of 17.15.
