document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=959326>Question 959326</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The Highway Safety Institute conducted test crashes at 6 mph, calculating the costs for the damage caused. The costs for the five test crashes were $7480, $4910, $9050, $6375, and $4275.  Use these data to test the claim that the mean cost of a 6mph crash is different from $5000.  Use a 5% level of significance.<BR>\n" );
document.write( "Determine the critical value(s)  Could you please explain it to me - like I was a six year old (can't think of the name of the movie - but that is just how I feel - lol).  Thanks so much. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #586409 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=586409\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The Highway Safety Institute conducted test crashes at 6 mph, calculating the costs for the damage caused. <BR>\n" );
document.write( "The costs for the five test crashes were $7480, $4910, $9050, $6375, and $4275. Use these data to test the claim that the mean cost of a 6mph crash is different from $5000. Use a 5% level of significance to determine the critical value(s).<BR>\n" );
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document.write( "Answer was posted yesterday.<BR>\n" );
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document.write( "Ho:: u = 5000<BR>\n" );
document.write( "Ha:: u # 5000 (claim)<BR>\n" );
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document.write( "sample mean = 6418 ; sample std = 1931.56<BR>\n" );
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document.write( "Since your sample is < 30 items, use t-values.<BR>\n" );
document.write( "Critical t-values for alpha = 5% with 4 degrees of freedom<BR>\n" );
document.write( "= invT(0.025,4) = +/-2.7765<BR>\n" );
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document.write( "That this means you should reject Ho if the test statistic<BR>\n" );
document.write( "is greater than 2.7765 standard deviations above or below<BR>\n" );
document.write( "the mean of 5000.<BR>\n" );
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document.write( "test stat depends on the mean of the sample<BR>\n" );
document.write( "t(6418) = (6418-5000)/[1931.56/sqrt(5)] = 1.6416<BR>\n" );
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document.write( "Conclusion:: Since the test stat is only 1.6 standard<BR>\n" );
document.write( "deviation above the mean you should fail to reject Ho.<BR>\n" );
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document.write( "Conclusion:: The test results do not support the claim that the<BR>\n" );
document.write( "mean is different than 5000 at a 5% level of significance.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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