document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=523930>Question 523930</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There are 20 people attending an event. A door prize is awarded to attendees if they choose the same number as you randomly pick. Numbers include 1,2,3,4,5.\r<BR>\n" );
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document.write( "How many prizes should you expect to be won?\r<BR>\n" );
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document.write( "How many prizes do you need to be 93% confident you have enough for all winners?\r<BR>\n" );
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document.write( "My attempt. I'm pretty sure the number randomly picked would be µ = 3.\r<BR>\n" );
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document.write( "Can I say that 1/4 people will pick each of the 5 numbers? So 4 people would choose 3 as their number. Therefore, I would expect 4 people to win.\r<BR>\n" );
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document.write( "I am lost on the confident part. We have not gone over that yet. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #347514 by </B><A HREF=/tutors/aboutme.mpl?userid=edjones><B>edjones(8007)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=edjones><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=edjones><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=347514\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How many prizes should you expect to be won?  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=mu=np+=+20+%2A+.2+=+4 ALIGN=MIDDLE  ALT=\"mu=np+=+20+%2A+.2+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "How many prizes do you need to be 93% confident you have enough for all winners?<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sigma=sqrt%28npq%29=sqrt%2820%2A.2%2A.8%29=1.789 ALIGN=MIDDLE  ALT=\"sigma=sqrt%28npq%29=sqrt%2820%2A.2%2A.8%29=1.789\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "z[.93](one tailed)=1.476<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-mu%29%2Fsigma=1.476 ALIGN=MIDDLE  ALT=\"%28x-mu%29%2Fsigma=1.476\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(x-4)/1.789=1.476 Number of prizes you need = x<BR>\n" );
document.write( "x-4=2.64<BR>\n" );
document.write( "x=6.64 or 7 prizes you need to be 93% confident.<BR>\n" );
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document.write( "Ed </SPAN>\n" );
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