document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=557413>Question 557413</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A random sample of 100 recorded deaths in an urban city during the past year showed an average life span of 71.8 years, with a standard deviation of 8.9 years. Does this seem to indicate that the average life span today is greater than the 70 years? (Use a 0.05 level of significance.) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #362642 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=362642\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A random sample of 100 recorded deaths in an urban city during the past year showed an average life span of 71.8 years, with a standard deviation of 8.9 years. Does this seem to indicate that the average life span today is greater than the 70 years? (Use a 0.05 level of significance.)<BR>\n" );
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document.write( "Ho: u = 70<BR>\n" );
document.write( "Ha: u > 70 (claim)<BR>\n" );
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document.write( "z(71.8) = (71.8-70)/[8.9/sqrt(100)] = 2.0224<BR>\n" );
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document.write( "p-value = 2*P(z > 2.0224) = 0.0431<BR>\n" );
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document.write( "Since the p-value is less than 5%, reject Ho.<BR>\n" );
document.write( "The test results support the claim.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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