document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=716456>Question 716456</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sample with size n = 100 has mean = 30. Assuming the population standard deviation is 8, construct 95% confidence interval for population mean. Use formula  z&#945;/2 = 1.96  <BR>\n" );
document.write( "Answer ? Help?<BR>\n" );
document.write( " <BR>\n" );
document.write( "	between 28.4 and 31.6<BR>\n" );
document.write( " <BR>\n" );
document.write( "	between 27.0 and 33.0<BR>\n" );
document.write( " <BR>\n" );
document.write( "	between 26.1 and 34.2<BR>\n" );
document.write( " <BR>\n" );
document.write( "	between 24.1 and 35.9\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\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 #439872 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=439872\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Lower Limit: \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "L = mean - za/2 * (standard deviation)/sqrt(n)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "L = 30 - 1.96 * (8)/sqrt(100)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "L = 30 - 1.96 * (8)/10\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "L = 30 - 1.96 * 0.8\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "L = 30 - 1.568\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "L = 28.432\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Upper Limit: \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "U = mean + za/2 * (standard deviation)/sqrt(n)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "U = 30 + 1.96 * (8)/sqrt(100)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "U = 30 + 1.96 * (8)/10\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "U = 30 + 1.96 * 0.8\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "U = 30 + 1.568\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "U = 31.568\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "So the 95% confidence interval is (L, U) = (28.432, 31.568)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Round this to one decimal place to get (28.4, 31.6)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "So the answer is <font color=\"red\">Choice A) between 28.4 and 31.6</font> </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );