document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1087049>Question 1087049</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is confidence interval if Population Mean = 70 and Margin of Error is 20?\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #701355 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=701355\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=\"black\" face=\"times\" size=\"3\">I think you meant to say \"sample mean\" instead of \"population mean\". The whole goal of a confidence interval is to estimate the parameter, which in this case is the population mean. If you know the parameter, then why bother estimate it with a confidence interval? \r<BR>\n" );
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document.write( "The sample mean is xbar = 70\r<BR>\n" );
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document.write( "The confidence interval is of the form (L, U) where L is the lower endpoint and U is the upper endpoint\r<BR>\n" );
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document.write( "If the margin of error is E, then\r<BR>\n" );
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document.write( "L = xbar - E<BR>\n" );
document.write( "L = 70 - 20<BR>\n" );
document.write( "L = 50\r<BR>\n" );
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document.write( "and\r<BR>\n" );
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document.write( "U = xbar + E<BR>\n" );
document.write( "U = 70 + 20<BR>\n" );
document.write( "U = 90\r<BR>\n" );
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document.write( "Making the confidence interval to be (L, U) = (50, 90) which can be written as <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=50+%3C+mu+%3C+90 ALIGN=MIDDLE  ALT=\"50+%3C+mu+%3C+90\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Note: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=mu ALIGN=MIDDLE  ALT=\"mu\"   DISABLED_style= \"max-width:90%; height:auto;\" > is the greek letter mu often used in statistics to represent the population mean</font> </SPAN>\n" );
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