Question 284397: High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as “Low” (under 88 decibels), “Medium” (88 to 91 decibels), or “High” (92 decibels or more). There are three flight phases (Climb, Cruise, Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase?
Noise Level Climb Cruise Descent Row Total
Low 6 2 6 14
Medium 18 3 8 29
High 1 3 14 18
================================================
Col Total 25 8 28 61
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as “Low” (under 88 decibels), “Medium” (88 to 91 decibels), or “High” (92 decibels or more). There are three flight phases (Climb, Cruise, and Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase? (Data are from Capt. Robert E. Hartl, retired.)
----------------
Noise
Noise Level Climb Cruise Descent Row Total
Low.......... 6.... 2...... 6...... 14
Medium...... 18.... 3...... 8...... 29
High......... 1.... 3..... 14...... 18
Col Total... 25.... 8..... 28...... 61
=============================================
Ho: row and column factors are independent
Ha: they are not
--------------
Run a Chi-Sq Test of independence on the 3x3 set of data
Test statistic: 15.16013
p-value: 0.00438
df = 2*2 = 4
Conclusion:Since p-value is less that 1%, reject Ho.
row and column factors are dependent; noise depends on flight level
==================================================================
Cheers,
Stan H.
|
|
|
