document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=302245>Question 302245</A>: <I><SPAN STYLE=\"word-break: break-all;\"> One of your friends knows that you are taking a statistics course and asks for your help with her chemistry lab report.  She has five measurements on the melting point of a compound: 122.4, 121.8, 122.0. 123.0, and 122.3.  <BR>\n" );
document.write( "a)The lab manual asks for a 95% confidence interval estimate for the melting point.  Show her how to find this estimate.<BR>\n" );
document.write( "b) explain to your friend what a 95% confidence interval is.<BR>\n" );
document.write( "c)would a 90% confidence interval be narrower than the 95% interval? Explain. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #216775 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=216775\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> five measurements on the melting point of a compound: <BR>\n" );
document.write( "122.4, 121.8, 122.0. 123.0, and 122.3. <BR>\n" );
document.write( "a)The lab manual asks for a 95% confidence interval estimate for the melting point. Show her how to find this estimate.<BR>\n" );
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document.write( "sample mean: 122.3<BR>\n" );
document.write( "sample std: 0.4099<BR>\n" );
document.write( "standard error = invT(0.975 with df=4)*0.4099/sqrt(5)= 2.7764*0.4099/sqrt(5)<BR>\n" );
document.write( "= 0.5090<BR>\n" );
document.write( "---<BR>\n" );
document.write( "95% CI: 122.3-0.4099 < u < 122.3+0.4099<BR>\n" );
document.write( "95% CI: 121.79 < u < 122.71<BR>\n" );
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document.write( "b) explain to your friend what a 95% confidence interval is.<BR>\n" );
document.write( "I'll leave that to you.  Try it on some of your friends.<BR>\n" );
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document.write( "c)would a 90% confidence interval be narrower than the 95% interval?<BR>\n" );
document.write( "Higher confidence requires a broader interval.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );