document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=918679>Question 918679</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Based on a study conducted last year, the incidence of heavy <BR>\n" );
document.write( "drinking among teenagers was 15%. You are in charge of monitoring <BR>\n" );
document.write( "this rate and conducted the annual survey. Of the 234 teenagers in <BR>\n" );
document.write( "the survey, 40 of them were heavy drinkers. If you want to know if the <BR>\n" );
document.write( "incidence rate has changed <BR>\n" );
document.write( "a)	What are the null and alternate hypotheses?\r<BR>\n" );
document.write( "\n" );
document.write( "b)	What is the test statistic to be used?\r<BR>\n" );
document.write( "\n" );
document.write( "c) Using a 5% significance level, can we conclude that the incidence <BR>\n" );
document.write( "rate has changed?\r<BR>\n" );
document.write( "\n" );
document.write( "d) What could be other reasons for a statistically significant reason if <BR>\n" );
document.write( "there is not truly one?<BR>\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 #557166 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=557166\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Ho: p = 0.15 claim<BR>\n" );
document.write( "Ha: p &#8800;  .15\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "-----------------------------------------\r<BR>\n" );
document.write( "\n" );
document.write( "sample proportion = p-hat = 40/234 = 0.17<BR>\n" );
document.write( "---<BR>\n" );
document.write( "test stat:: z(0.17) = (0.17-0.15)/sqrt[0.15*0.85/234] = .02 /.0233 = .8568<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "5% significance level, critical value =  ±  1.96 <BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "Conclusiion: <BR>\n" );
document.write( "Since .8568 < 1.96, accept the average of 15%.<BR>\n" );
document.write( "The test results have not shown sufficient evidence to support it has changed.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );