document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=142044>Question 142044</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A fair coins is tossed 5 times. \r<BR>\n" );
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document.write( "What is the probability of obtaining exactly 3 heads?\r<BR>\n" );
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document.write( "I found a formula that looks like C(5,3)=5!/[3!(5-3)!]\r<BR>\n" );
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document.write( "My problem is, I don't know if this formula is right, or how to solve it. I believe this is supposed to tell you the number of possible outcomes??? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #103424 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=103424\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A fair coins is tossed 5 times. <BR>\n" );
document.write( "What is the probability of obtaining exactly 3 heads? <BR>\n" );
document.write( "I found a formula that looks like C(5,3)=5!/[3!(5-3)!] <BR>\n" );
document.write( "My problem is, I don't know if this formula is right, or how to solve it. I believe this is supposed to tell you the number of possible outcomes???<BR>\n" );
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document.write( "You are correct; there are C(5,3) = 10 ways the 3 heads<BR>\n" );
document.write( "can show up in the five tosses.<BR>\n" );
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document.write( "Each of those patterns has probability (1/2)^3(1/2)^2 = (1/2)^5 = 1/32<BR>\n" );
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document.write( "since the patterns are mutually exclusive you have to add up all those<BR>\n" );
document.write( "probabilities to get:<BR>\n" );
document.write( "10*1/32 = 5/16  as the probability of getting 3 heads when you throw<BR>\n" );
document.write( "a coin 5 times.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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