document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=188975>Question 188975</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.) 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 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #141736 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=141736\">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, Descent).<BR>\n" );
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document.write( "Research question: At &#945; = .05, is the cockpit noise level independent of flight phase? <BR>\n" );
document.write( "(Data are from Capt. Robert E. Hartl, retired.) 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" );
document.write( "-------------<BR>\n" );
document.write( "Ho: The row and column factors are not related<BR>\n" );
document.write( "Ha: They are related<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "Run a Chi-Sq on the 3 by 3 set of data.<BR>\n" );
document.write( "I get test statistic Chi-Sq = 15.16<BR>\n" );
document.write( "p-value = 0.0044<BR>\n" );
document.write( "df = (3-1)(3-1)= 4<BR>\n" );
document.write( "-----------------------------<BR>\n" );
document.write( "Conclusion:<BR>\n" );
document.write( "Since the p-value is less than 5%, reject Ho.<BR>\n" );
document.write( "Noise levels are related to flight configuration.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );