Answer is: the pressure is 1.12 atm.
n(O₂) = 0.00825 mol, amount of substance.
V = 174 mL ÷ 1000 mL/L = 0.174 L, volume of gas.
T = 15°C = 288.15 K; temperature.
R = 0.08206 L·atm/mol·K, universal gas constant.
Ideal gas law: p·V = n·R·T.
p = n·R·T / V.
p = 0.00825 mol · 0.08206 L·atm/mol·K · 288.15 K / 0.174 L.
p = 1.12 atm.