document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230751>Question 230751</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The probability is 1 in 4,000,000 that a single auto trip in the United States will result in a fatality. Over a lifetime, an average U.S. driver takes 50,000 trips. <BR>\n" );
document.write( "(a) What is the probability of a fatal accident over a lifetime? Explain your reasoning carefully. Hint: Assume independent events. Why might the assumption of independence be violated? <BR>\n" );
document.write( "(b) Why might a driver be tempted not to use a seat belt “just on this trip”?<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 #170914 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=170914\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The robability is 1 in 4,000,000 that a single auto trip in the United States will result in a fatality. Over a lifetime, an average U.S. driver takes 50,000 trips. <BR>\n" );
document.write( "(a) What is the probability of a fatal accident over a lifetime? Explain your reasoning carefully. Hint: Assume independent events. Why might the assumption of independence be violated?<BR>\n" );
document.write( "The probability of no fatal accident in 50,000 trips is <BR>\n" );
document.write( "(3,999,999/4,000,000)^(50,000) = 0.987578.....<BR>\n" );
document.write( "So the probability of having a fatal accident is 1-0.987578... = 0.0124...<BR>\n" );
document.write( "The probability changes from youth to middle age to old age.<BR>\n" );
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document.write( "(b) Why might a driver be tempted not to use a seat belt “just on this trip”?<BR>\n" );
document.write( "Because the probability is so small on each individual trip.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );