document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=185150>Question 185150</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0072966939/algebrahomeworkh>Applied Statistics</A><BR>\n" );
document.write( ": <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. (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? (b) Why might a driver be tempted not to use a seat belt “just on this trip”?\r<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 #139037 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=139037\">put this solution on YOUR website!</A><BR><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" );
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document.write( "It's a binomial problem with n = 50,000, p = 1/4,000,000, x = 1<BR>\n" );
document.write( "Using a TI-83 you get binompdf(50,000,1/400,000,000,1) = 0.01234<BR>\n" );
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document.write( "Independence might be doubted because some people have a history of<BR>\n" );
document.write( "having accidents and others never have an accident because they are<BR>\n" );
document.write( "more careful in their driving habits.<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( "The probability on any given grip is 1/400,000 but it is more than 1/100<BR>\n" );
document.write( "for a lifetime of 50,000 trips.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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