document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=145632>Question 145632</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 15.24 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<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #106265 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=106265\">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. <BR>\n" );
document.write( "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( "---------------------------------<BR>\n" );
document.write( "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( "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: noise level and flight phase are independent<BR>\n" );
document.write( "Ha: they are dependent<BR>\n" );
document.write( "------------<BR>\n" );
document.write( "I ran a Chi-Sq Test and got the following results:<BR>\n" );
document.write( "test statistic: Chi-Sq = 15.16..<BR>\n" );
document.write( "p-value: 0.00438...<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "Conclusion: since p-value is less than 5%, reject Ho.<BR>\n" );
document.write( "Noise level and flight phase are dependent.<BR>\n" );
document.write( "===============<BR>\n" );
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" );