document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=190466>Question 190466</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A study of iron deficiency among infants compared samples of infants following different<BR>\n" );
document.write( "feeding regimens. One group contained breast-fed infants, while the children in other group<BR>\n" );
document.write( "were fed a standard baby formula without any iron supplements. Here are summary results<BR>\n" );
document.write( "on blood hemoglobin levels at 12 months of age.<BR>\n" );
document.write( "Group n Mean s<BR>\n" );
document.write( "Breast-fed 23 13.3 1.7<BR>\n" );
document.write( "Formula 19 12.4 1.8<BR>\n" );
document.write( "a. Is there significant evidence that the mean hemoglobin level is higher among breastfed<BR>\n" );
document.write( "babies? State null hypothesis and alternate hypothesis and conduct a t-test.<BR>\n" );
document.write( "b. Give a 95% confidence interval for the mean difference in hemoglobin level between<BR>\n" );
document.write( "the two populations of infants. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #143052 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=143052\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A study of iron deficiency among infants compared samples of infants following different<BR>\n" );
document.write( "feeding regimens. One group contained breast-fed infants, while the children in other group<BR>\n" );
document.write( "were fed a standard baby formula without any iron supplements. Here are summary results<BR>\n" );
document.write( "on blood hemoglobin levels at 12 months of age.<BR>\n" );
document.write( "Group...... n Mean s<BR>\n" );
document.write( "Breast-fed 23 13.3 1.7<BR>\n" );
document.write( "Formula... 19 12.4 1.8<BR>\n" );
document.write( "a. Is there significant evidence that the mean hemoglobin level is higher among breastfed babies? State null hypothesis and alternate hypothesis and conduct a t-test.<BR>\n" );
document.write( "Ho: u(breastfed)-u(formula) = 0<BR>\n" );
document.write( "Ha: u(breastfed)-u(formula > 0<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "I ran a 2-sample T-test on a TI caluclator and got the following:<BR>\n" );
document.write( "test statistic: t= 1.6537<BR>\n" );
document.write( "p-value.......: P(t.1.6537 with df=37.6) = 0.05325<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Conclusion: Since the p-value is greater than 5%, fail to reject Ho.<BR>\n" );
document.write( "Note: The p-value is so close to 5% more testing should be done.<BR>\n" );
document.write( "=======================================================================\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "b. Give a 95% confidence interval for the mean difference in hemoglobin level between the two populations of infants.<BR>\n" );
document.write( "I ran a 2-Sample T-interval on a TI caluculator and got the folowing<BR>\n" );
document.write( "95% C.I.:::: ( -0.2021 , 2.0021)<BR>\n" );
document.write( "Conclusion: Since zero is in the 95% C.I., fail to reject Ho.<BR>\n" );
document.write( "=======================================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );