document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=135301>Question 135301</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/9780073534961/algebrahomeworkh>Statistics</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> A random sample of 76 four-year-olds attending day care centers showed that the yearly tuition averaged $3648.  The standard deviation of the sample was $630 and the sample size was 50.  Find the 90% confidence interval of the true mean.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #99139 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=99139\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A random sample of 76 four-year-olds attending day care centers showed that the yearly tuition averaged $3648.  The standard deviation of the sample was $630 and the sample size was 50.  Find the 90% confidence interval of the true mean.<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "Note: you gave two numbers for the sample size: 76 and 50. I chose n=50.<BR>\n" );
document.write( "x-bar = 3648<BR>\n" );
document.write( "standard error = E = 1.645 * [630/sqrt(50)]= 146.56<BR>\n" );
document.write( "CI: x-bar - E < mu < x-bar + E<BR>\n" );
document.write( "================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );