document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=456932>Question 456932</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Could you please help me to solve this problem?\r<BR>\n" );
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document.write( "Must show work\r<BR>\n" );
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document.write( "A sample of 20 elements produced a mean of 58 and a standard deviation of 12. Assuming the population has a normal distribution, find the 90% confidence interval for the population mean. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #313568 by </B><A HREF=/tutors/aboutme.mpl?userid=edjones><B>edjones(8007)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=edjones><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/cgi-bin/show-face.mpl?user=edjones><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=313568\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> n=20, m=58, s=12<BR>\n" );
document.write( "(a, b)=m +- z[a/2] * s/sqrt(n)<BR>\n" );
document.write( "(a, b)=58+-1.645*(12/sqrt(20)) The z for .9 confidence level 2 tailed is +-1.645<BR>\n" );
document.write( "=58+-4.41<BR>\n" );
document.write( "=(62.41, 53.59)<BR>\n" );
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document.write( "Ed </SPAN>\n" );
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