document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1172148>Question 1172148</A>: <I><SPAN STYLE=\"word-break: break-all;\"> CASE STUDY. TO ANSWER QUESTIONS 1 AND 2.<BR>\n" );
document.write( "You recently received a job with a company that sells products. You want to conduct an advertising campaign for the product. Your boss said that last year the advertisement cost was GH¢ 44. You want to see if it has changed. The following are the cost for the previous years.<BR>\n" );
document.write( "55, 42, 125, 62, 134, 73, 39, 69, 23, 94, 73, 24, 51, 55, 26, 66, 41, 67, 15, 53, 56, 91, 20, 78, 70, 25, 62, 115, 17, 36, 58, 56, 33, 75, 20, 16. Use this information to answer question 1 and 2.\r<BR>\n" );
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document.write( "Question 1<BR>\n" );
document.write( "a) What hypotheses would you use? Are you to conduct a one tail or a two-tail test? What is the claim?<BR>\n" );
document.write( "b) Is the sample considered small or large? Explain.<BR>\n" );
document.write( "c) What assumption must you meet before you can conduct the test?<BR>\n" );
document.write( "d) Which probability distribution would you use and why? What is the alternative to this?<BR>\n" );
document.write( "e) What critical value(s) would you use at 5% significance level?\r<BR>\n" );
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document.write( "Question 2<BR>\n" );
document.write( "a) Calculate the test statistics. Use the sample mean as 55.97 and standard deviation as 30.3. Show at least three iterations to arrive at the final answer.<BR>\n" );
document.write( "b) What is your decision? Explain. Explain the other alternative as well<BR>\n" );
document.write( "c) What is your conclusion?<BR>\n" );
document.write( "d) What p-value(s) would you use?<BR>\n" );
document.write( "e) At 5% significance level with the p-value, what would be your decision and why?<BR>\n" );
document.write( "f) From (e) above, what would be the summary of your finding?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #797107 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=797107\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> two tail test, because you are looking for a change, not certain which way it might be if there is one.<BR>\n" );
document.write( "Ho: No change mu now=mu past<BR>\n" );
document.write( "Ha: there is a change mu now NE mu past<BR>\n" );
document.write( "sample is > 30 and is considered large, although 30 is not a magic number by any means.<BR>\n" );
document.write( "The sample was randomly taken, and after that assume the distribution is normal.<BR>\n" );
document.write( "Because n >30 probably they are looking for a z-test, but no sd given and a t-test is reasonable as well. <BR>\n" );
document.write( "critical value would depend upon which test. At the 5% level, |z| > 1.96  and |t| > the critical value of t(0.975, df=36), which is 2.03\r<BR>\n" );
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document.write( "test stat t=(55.97-44)/30.3/sqrt(37)=2.40<BR>\n" );
document.write( "could be done with z using the same numbers\r<BR>\n" );
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document.write( "Conclude in either case to reject Ho and there has been a change in the price.<BR>\n" );
document.write( "p-value is 0.0215<BR>\n" );
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