At an altitude of 11,000 m (a typical cruising altitude for a jet airliner), the air temperature is - 56.5°C and the air density is 0.364 kg/m3. What is the pressure of the atmosphere at that altitude? (Note: The temperature at this altitude is not the same as at the surface of the earth, so the calculation of Example 18.4 in Section 18.1 doesn't apply.)