document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=579009>Question 579009</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose SPS professors have an average life normally distributed of 82 years, with a population standard deviation of 5 years.  &#61514;\r<BR>\n" );
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document.write( "a) What percent of SPS professors will make it past the age of 70?<BR>\n" );
document.write( "b) What percent of SPS professors will not live more than 80 years?<BR>\n" );
document.write( "c) Calculate the 95th percentile.<BR>\n" );
document.write( "d) What proportion of SPS professors will live between 85 and 90 years? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #370830 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=370830\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Suppose SPS professors have an average life normally distributed of 82 years, with a population standard deviation of 5 years. &#61514; <BR>\n" );
document.write( "a) What percent of SPS professors will make it past the age of 70?<BR>\n" );
document.write( "z(70) = (70-82)/5 = -12/5<BR>\n" );
document.write( "P(x > 70) = P(z > -12/5) = 0.9918<BR>\n" );
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document.write( "b) What percent of SPS professors will not live more than 80 years?<BR>\n" );
document.write( "z(80) = (80-82)/5 = -2/5<BR>\n" );
document.write( "P(x <= 80) = P(z <= -2/5) = 0.3446<BR>\n" );
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document.write( "c) Calculate the 95th percentile.<BR>\n" );
document.write( "InvNorm(0.95) = 1.645<BR>\n" );
document.write( "x = 1.645*5+82 = 90.225<BR>\n" );
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document.write( "d) What proportion of SPS professors will live between 85 and 90 years?<BR>\n" );
document.write( "Using a TI-84: P(85<= x <=90) = normalcdf(85,90,82,5) = 0.2195<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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