document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1129301>Question 1129301</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What two assumptions must be met when you are using<BR>\n" );
document.write( "the z test to test differences between two means? Can the<BR>\n" );
document.write( "sample standard deviations s1 and s2 be used in place of<BR>\n" );
document.write( "the population standard deviations sigma1 and sigma2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #745856 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=745856\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Normal distribution and random sample are necessary.<BR>\n" );
document.write( "One may use s1 and s2, but then it is a 2-sample t-test, assuming here that the sample SD is an unbiased estimator of the population SD. </SPAN>\n" );
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