document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1186998>Question 1186998</A>: <I><SPAN STYLE=\"word-break: break-all;\"> According to the Internal Revenue Service, income tax returns one year averaged $1,332 in refunds for taxpayers. One<BR>\n" );
document.write( "explanation of this figure is that taxpayers would rather have the government keep back too much money during the<BR>\n" );
document.write( "year than to owe it money at the end of the year. Suppose the average amount of tax at the end of a year is a refund of<BR>\n" );
document.write( "$1,332 with a standard deviation of $725.<BR>\n" );
document.write( "a) What proportion of tax returns show a refund greater than $1,900?<BR>\n" );
document.write( "b) What proportion of the tax returns show that the taxpayer woes money to the government?<BR>\n" );
document.write( "c) What proportion of the tax returns show a refund between $200 and $800?<BR>\n" );
document.write( "d) Examine by the diagram. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #819676 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=819676\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "z>(1900-1332)/725 =0.78<BR>\n" );
document.write( "that probability is 0.2177<BR>\n" );
document.write( "-<BR>\n" );
document.write( "z< (-1332/725) =-1.84, and the probability of that is 0.0331<BR>\n" );
document.write( "-<BR>\n" );
document.write( "for 200, z=-1132/725 or -1.561<BR>\n" );
document.write( "for 800, z=-532/725 or -0.734<BR>\n" );
document.write( "The probability of z being between those two is 0.1722<BR>\n" );
document.write( "On a calculator, 2ndVARS2 normalcdf(200,800,1332,725) ENTER\r<BR>\n" );
document.write( "\n" );
document.write( "ask how much the teacher wants the z-value rounded to. It will change the result slightly.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );