document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1105771>Question 1105771</A>: <I><SPAN STYLE=\"word-break: break-all;\"> For each of the following problems, please provide the requested information. <BR>\n" );
document.write( "	.	(a)  What is the level of significance? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test? &#8232;<BR>\n" );
document.write( "	.	(b)  Identify the sampling distribution you will us: the standard normal or Student’s t. Explain the rationale for your choice. What is the value of the sample test statistic? &#8232;<BR>\n" );
document.write( "	.	(c)  Find (or estimate) the P &#8722; value. Sketch the sampling distribution and show the area corre- sponding to the P &#8722; value. &#8232;<BR>\n" );
document.write( "(d) Find the critical value(s). <BR>\n" );
document.write( "(e) Based on your answers for parts (a) to (d), will you reject or fail to reject the null hypothesis? Interpret your decision in the context of the application. \r<BR>\n" );
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document.write( "		Assume that x is normally distributed. James gets stuck in traffic on his way to work, everyday for many years! On average he was always stuck for &#956; = 20 minutes. After a construction expanded the highway from 3 to 4 lanes. The traffic started moving more smoothly. A random selection of five days showed the delay to have a mean x &#772; = 15.2 minutes with a sample standard deviation of s = 6.3 minutes. Does this indicate that the population mean delay time due to traffic after the highway-expansion is shorter that what it used to be? Use significance level of 0.05. &#8232;<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 #721368 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=721368\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This should be a one-tailed t-test, because a sample is taken and the sd of the sample is used to estimate the variance.  One-tail may be done, because the expectation will be the delay should be shorter.\r<BR>\n" );
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document.write( "Ho: delay is same or worse<BR>\n" );
document.write( "Ha: delay is less<BR>\n" );
document.write( "alpha=0.05, critical value is t 0.95 df=4=-2.132<BR>\n" );
document.write( "t=(15.2-20)/6.3/sqrt(5)<BR>\n" );
document.write( "t=-4.8*sqrt(5)/6.3=-1.70<BR>\n" );
document.write( "p-value=0.08<BR>\n" );
document.write( "There is insignificant evidence to say that the mean time delay is less.<BR>\n" );
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