document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1125872>Question 1125872</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Assume that 32.9&#8203;% of people have sleepwalked. Assume that in a random sample of 1521 &#8203;adults, 542 have sleepwalked.<BR>\n" );
document.write( "a. Assuming that the rate of 32.9&#8203;% is&#8203; correct, find the probability that 542 or more of the 1521 adults have sleepwalked.<BR>\n" );
document.write( "b. Is that result of 542 or more significantly&#8203; high?<BR>\n" );
document.write( "c. What does the result suggest about the rate of 32.9&#8203;%? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #742214 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=742214\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a.  549/1521=36.1%<BR>\n" );
document.write( "z=(p-phat)/sqrt(p*(1-p)/n)<BR>\n" );
document.write( "=0.032/sqrt(0.329*0.671/1521)<BR>\n" );
document.write( "=2.66<BR>\n" );
document.write( "b.  probability z>2.66 is 0.0039<BR>\n" );
document.write( "This is about 2/5 ths of one percent, considered to be statistically significant.  \r<BR>\n" );
document.write( "\n" );
document.write( "c. That suggests that perhaps the quoted rate of 32.9% is too low. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );