Manufacturing and Product Development
Raytheon Aircraft is now manufacturing business jets with a molded carbon fiber fuselage instead of aluminum. This reduces the overall weight of the plane, speeds production time, and increases cabin space. The total wall thickness of a carbon fiber fuselage is 0.81 inch versus 3 inches for aluminum, and the variability in thickness is theoretically much smaller also. Independent random samples of the two fuselage types were obtained, and the thickness was measured (in inches) on each. The data are given in the following table.
|
Fuselage type
|
Sample size
|
Sample variance
|
|
Aluminum
|
9
|
0.0196
|
|
Carbon
|
11
|
0.0025
|
Is there any evidence to suggest that the variability in fuselage thickness is less for carbon fiber fuselages? Use a = 0.01.