Assuming a Cabin pressure of 6,500 ft internally, calculate the stress levels at 3,000, 9,000, 15,000, 25,000, 29,000 and 37,500 ft. with a 7 m diameter fuselage and skin thickness of 0.7 mm and 1.00 mm. Comment upon the stress levels, the changes, and any conclusions. If the fuselage was 3.5 m diameter what would be different?