document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1058350>Question 1058350</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 80% = Yes<BR>\n" );
document.write( "20% = No\r<BR>\n" );
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document.write( "A)Sample of 15<BR>\n" );
document.write( "Probability more than 4 but fewer than 8 = Yes\r<BR>\n" );
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document.write( "B)Sample of 2000<BR>\n" );
document.write( "Probability that more than 380 = No<BR>\n" );
document.write( "probabii<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #673400 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=673400\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Want probability of 5,6,7<BR>\n" );
document.write( "15C5(.8)^5(.2)^10=3003*0.32768*0.0000001024=0.0001<BR>\n" );
document.write( "15C6(.8^6)(.2)^9=0.0007<BR>\n" );
document.write( "15C7(.8^7)(.2^8)=0.0035<BR>\n" );
document.write( "Total is 0.0043.<BR>\n" );
document.write( "This should be small, since the expected value is 12 and the variance 12*(0.2)=2.4, so Std dev. between 1.5 and 1.6. These values are 3-4+ sd below the mean.<BR>\n" );
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document.write( "Treat as a normal distribution with mean np=400<BR>\n" );
document.write( "Variance is np(1-p)=400(.8)=320<BR>\n" );
document.write( "Std dev is sqrt (320)=17.89<BR>\n" );
document.write( "probability it is >380 is<BR>\n" );
document.write( "probability that z is > (x-mean)/sd=(380-400)/17.89=-1.11<BR>\n" );
document.write( "That is 0.8682<BR>\n" );
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