document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=268152>Question 268152</A>: <I><SPAN STYLE=\"word-break: break-all;\"> High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this<BR>\n" );
document.write( "hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld<BR>\n" );
document.write( "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<BR>\n" );
document.write( "question: At &#945; = .05, is the cockpit noise level independent of flight phase? (Data are from<BR>\n" );
document.write( "Capt. Robert E. Hartl, retired.)\r<BR>\n" );
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document.write( "Noise Level          Climb            Cruise          Descent      Row Total<BR>\n" );
document.write( "Low                    6                 2               6            14<BR>\n" );
document.write( "Medium                 18                3               8            29<BR>\n" );
document.write( "High                   1                 3               14           18<BR>\n" );
document.write( "Col Total              25                8               28           61 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #196779 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=196779\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 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 &#945; = .05, is the cockpit noise level independent of flight phase? (Data are from Capt. Robert E. Hartl, retired.)<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "Noise<BR>\n" );
document.write( "Noise Level Climb Cruise Descent Row Total<BR>\n" );
document.write( "Low.......... 6.... 2...... 6...... 14<BR>\n" );
document.write( "Medium...... 18.... 3...... 8...... 29<BR>\n" );
document.write( "High......... 1.... 3..... 14...... 18<BR>\n" );
document.write( "Col Total... 25.... 8..... 28...... 61 <BR>\n" );
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document.write( "Ho: row and column factors are independent<BR>\n" );
document.write( "Ha: they are not<BR>\n" );
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document.write( "Run a Chi-Sq Test of independence on the 3x3 set of data<BR>\n" );
document.write( "Test statistic: 15.16013<BR>\n" );
document.write( "p-value: 0.00438 <BR>\n" );
document.write( "df = 2*2 = 4<BR>\n" );
document.write( "Conclusion:Since p-value is less that 1%, reject Ho.<BR>\n" );
document.write( "row and column factors are dependent; noise depends on flight level<BR>\n" );
document.write( "==================================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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