Question

A manufacturing company makes aircraft altimeters.   These devices are tested in a pressure chamber,
and errors in altitude are recorded as either positive (for readings that are too high) or negative (for readings
that are too low).   Using a long established production method, the errors for these devices were normally
distributed with a standard deviation of 47.3 ft.

Now, a new production method is to be used; however, there is some concern that the new method produces
less accurate altimeters. To test this claim, a simple random sample of 81 altimeters is tested and the sample
has a standard deviation of s = 52.3 ft.  

Use this sample data and a significance level of α =.05 to test the claim that the new production line has
errors with a standard deviation that is higher than 47.3 ft.

Answer 1