document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1158634>Question 1158634</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The average salary of graduates entering the actuarial field is reported to be $40,000. To test this, a statistics professor<BR>\n" );
document.write( "surveys 20 graduates and finds their average salary to be $43,228. Assume the population is normally distributed with a<BR>\n" );
document.write( "population standard deviation is $4000. Using 𝛼 = 0.05, has he shown the reported salary to be incorrect? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #781635 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=781635\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Random sample and other assumptions assumed<BR>\n" );
document.write( "Ho: salary if $40000<BR>\n" );
document.write( "Ha: it is not<BR>\n" );
document.write( "alpha=0.05 p{reject Ho|Ho true}<BR>\n" );
document.write( "test stat is a z=(xbar-mean)/sigma/sqrt(n)<BR>\n" );
document.write( "reject if |z|>1.96<BR>\n" );
document.write( "=(3228)/4000/sqrt(20)<BR>\n" );
document.write( "z=3.61<BR>\n" );
document.write( "reject Ho p-value<0.0004<BR>\n" );
document.write( "the reported salary is not $40,000 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );