document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1086127>Question 1086127</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Assume that blood pressure readings have a mean of 120 and a standard deviation of 8. If 100 people are randomly selected, find the probability that their mean blood pressure will be greater than 122.\r<BR>\n" );
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document.write( "a. 0.8819\r<BR>\n" );
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document.write( "b. 0.9938\r<BR>\n" );
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document.write( "c. not enough information to determine\r<BR>\n" );
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document.write( "d. 0.0062\r<BR>\n" );
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document.write( "e. 0.8615 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #700277 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=700277\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a z-test since population sd is assumed to be known<BR>\n" );
document.write( "z=(x-mean)/s/sqrt(n)<BR>\n" );
document.write( "z=(122-120)/8/sqrt(100)<BR>\n" );
document.write( "=2*10/8, inverting the denominator and multiplying.<BR>\n" );
document.write( "=2.5<BR>\n" );
document.write( "Want probability of z>2.5<BR>\n" );
document.write( "That is 0.0062<BR>\n" );
document.write( "It is much easier for a random BP to be above 122 than it is the mean of 100 of them, coming from a population where the mean is 120.<BR>\n" );
document.write( "D. </SPAN>\n" );
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