document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=847147>Question 847147</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Recall that the National Bridge Inspection Standard (NBIS) rating scale ranges from 0 (poorest) to 9 (highest). Engineers forecast that 9% of all major Denver bridges will have ratings of 4 or below in the year 2020.\r<BR>\n" );
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document.write( "a. Use the forecast to approximate the probability that in a random sample of 70 major Denver bridges, at least half will have an inspection rating of 4 or below in 2020.\r<BR>\n" );
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document.write( "b. Suppose that you actually observe at least 35 of the sample of 75 bridges with inspection ratings of 4 or below in 2020. What inference can you make? Why? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #510202 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=510202\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Recall that the National Bridge Inspection Standard (NBIS) rating scale ranges from 0 (poorest) to 9 (highest). Engineers forecast that 9% of all major Denver bridges will have ratings of 4 or below in the year 2020.<BR>\n" );
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document.write( "a. Use the forecast to approximate the probability that in a random sample of 70 major Denver bridges, at least half will have an inspection rating of 4 or below in 2020.<BR>\n" );
document.write( "Binomial Problem with n = 70 and p(<=4) = 0.09<BR>\n" );
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document.write( "P(x >= 36) = 1 - binomcdf(70,0.09,35) = 0 to 8 decimal places<BR>\n" );
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document.write( "b. Suppose that you actually observe at least 35 of the sample of 75 bridges with inspection ratings of 4 or below in 2020. What inference can you make? Why?<BR>\n" );
document.write( "Ans: You could conclude that the Engineers forcast is wrong.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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document.write( " </SPAN>\n" );
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