document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1187843>Question 1187843</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The table below contains the birth weights in grams of 26 African American babies born at BayState Medical Center in Springfield, Massachusetts in 1986. Compute a 95% confidence interval for birth weight.\r<BR>\n" );
document.write( "\n" );
document.write( "Data\r<BR>\n" );
document.write( "\n" );
document.write( "Weight<BR>\n" );
document.write( "2546<BR>\n" );
document.write( "2775<BR>\n" );
document.write( "2889<BR>\n" );
document.write( "2945<BR>\n" );
document.write( "2931<BR>\n" );
document.write( "2931<BR>\n" );
document.write( "3017<BR>\n" );
document.write( "3029<BR>\n" );
document.write( "3087<BR>\n" );
document.write( "3290<BR>\n" );
document.write( "3365<BR>\n" );
document.write( "3367<BR>\n" );
document.write( "3407<BR>\n" );
document.write( "3799<BR>\n" );
document.write( "3849<BR>\n" );
document.write( "1139<BR>\n" );
document.write( "1724<BR>\n" );
document.write( "1955<BR>\n" );
document.write( "2118<BR>\n" );
document.write( "2148<BR>\n" );
document.write( "2315<BR>\n" );
document.write( "2383<BR>\n" );
document.write( "2420<BR>\n" );
document.write( "2379<BR>\n" );
document.write( "2447<BR>\n" );
document.write( "2492\r<BR>\n" );
document.write( "\n" );
document.write( "Find the point estimate for the birth weights. Round your answer to 2 decimal places.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Determine the value of tc. Round your answer to 5 decimal places.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Find the margin of error for the confidence interval. Round your answer to 1 decimal place.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Construct the confidence interval for birth weights. Enter your answer as an open interval of the form (a,b) and round to the nearest integer.\r<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 #818850 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=818850\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Here is how you do this;<BR>\n" );
document.write( "Put the numbers into the calculator<BR>\n" );
document.write( "Use 1-variable statistics which will give you the mean, which is the point estimate you want.<BR>\n" );
document.write( "Use s, not sigma, for your sd.<BR>\n" );
document.write( "The margin of error is t(0.975, df=25)*s/sqrt(n).  The t-value is 2.06, n=26<BR>\n" );
document.write( "add and subtract the margin of error to and from the mean for your interval. <BR>\n" );
document.write( "Check it by doing a confidence interval on your calculator for the data, which skips all those steps, but it is worth while doing this by hand to see that you get the same result. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );