document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=134531>Question 134531</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Can someone please help me to understand what to do with these two problems??? I am lost. \r<BR>\n" );
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document.write( "1) Give the variance of the following distribution. \r<BR>\n" );
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document.write( "X          P(X)<BR>\n" );
document.write( "0          0.20<BR>\n" );
document.write( "1          0.35<BR>\n" );
document.write( "2          0.10<BR>\n" );
document.write( "3          0.25<BR>\n" );
document.write( "4          0.10\r<BR>\n" );
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document.write( "A) 1.83<BR>\n" );
document.write( "B) 1.31<BR>\n" );
document.write( "C) 1.25<BR>\n" );
document.write( "D) 1.71\r<BR>\n" );
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document.write( "2) What is the standard deviation of the following probability distribution?\r<BR>\n" );
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document.write( "X          P(X)<BR>\n" );
document.write( "0          0.20<BR>\n" );
document.write( "2          0.05<BR>\n" );
document.write( "4          0.35<BR>\n" );
document.write( "6          0.25<BR>\n" );
document.write( "8          0.15\r<BR>\n" );
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document.write( "A) 2.6<BR>\n" );
document.write( "B) 4.7<BR>\n" );
document.write( "C) 5.4<BR>\n" );
document.write( "D) 3.9\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #98425 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=98425\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Can someone please help me to understand what to do with these two problems??? I am lost. <BR>\n" );
document.write( "1) Give the variance of the following distribution. <BR>\n" );
document.write( "X.. P(X)..X^2.X^2*P(X)<BR>\n" );
document.write( "0.. 0.20..00...0.00<BR>\n" );
document.write( "1.. 0.35...1...0.35<BR>\n" );
document.write( "2.. 0.10...4...0.40<BR>\n" );
document.write( "3.. 0.25...9...2.25<BR>\n" );
document.write( "4.. 0.10..16...1.60<BR>\n" );
document.write( "Add up the X^2*P(X) to get 4.6<BR>\n" );
document.write( "Find the mean: Sum[X*P(X)] = 0.35 + 2*0.1 + 3*.25 + 4*0.1 = 1.7 <BR>\n" );
document.write( "standard deviation = Sqrt[Sum[X^2*P(X)]-mu^2] = sqrt[4.6-1.7^2]<BR>\n" );
document.write( "=sqrt[1.71]\r<BR>\n" );
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document.write( "Sample Variance = [E(x^2*P(x))]-u^2]]^2 = [sqrt(1.71)]^2 = 1.71<BR>\n" );
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document.write( "A) 1.83<BR>\n" );
document.write( "B) 1.31<BR>\n" );
document.write( "C) 1.25<BR>\n" );
document.write( "D) 1.71 \r<BR>\n" );
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document.write( "2) What is the standard deviation of the following probability distribution?<BR>\n" );
document.write( "Follow the same pattern as above:<BR>\n" );
document.write( "Answer: 2.6<BR>\n" );
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document.write( "X P(X)<BR>\n" );
document.write( "0 0.20<BR>\n" );
document.write( "2 0.05<BR>\n" );
document.write( "4 0.35<BR>\n" );
document.write( "6 0.25<BR>\n" );
document.write( "8 0.15<BR>\n" );
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document.write( "A) 2.6<BR>\n" );
document.write( "B) 4.7<BR>\n" );
document.write( "C) 5.4<BR>\n" );
document.write( "D) 3.9 <BR>\n" );
document.write( "===========<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );