document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1153179>Question 1153179</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A researcher believes that smoking affects a person’s sense of smell. To test this, he takes a sample of 25 smokers and gives them a test of olfactory sensitivity. In this test, higher scores indicate greater sensitivity. For his sample, the mean score on the test is 14.8 with a standard deviation of 2.4. The researcher knows the mean score in the population is 16.2, but the population standard deviation is unknown.\r<BR>\n" );
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document.write( "(a) What are the null and alternative hypotheses in this study (stated mathematically)?<BR>\n" );
document.write( "(b) Should the researcher use a one-tailed or a two-tailed test?<BR>\n" );
document.write( "(c) Compute the appropriate test statistic for testing the hypothesis.<BR>\n" );
document.write( "(d) Using α = 0.01, do you conclude that smoking affects a person’s sense of smell? Be sure to include a discussion of the critical value in your answer.<BR>\n" );
document.write( "(e) What type of error might the researcher be making in part (d)? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #775554 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=775554\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Ho: mu is greater than or equal to 16.2<BR>\n" );
document.write( "Ha: mu is less than 16.2<BR>\n" );
document.write( "alpha is 0.05 P{reject Ho|Ho true}<BR>\n" );
document.write( "one tail test because suspect difference will only be less.<BR>\n" );
document.write( "test stat is a t df=24 0.95<BR>\n" );
document.write( "critical value is t<-1.711<BR>\n" );
document.write( "t=(14.8-16.2)/2.4/sqrt(25)<BR>\n" );
document.write( "t=-1.4*5/2.4=-2.92<BR>\n" );
document.write( "reject Ho because t is less than the critical value of -1.711. There is evidence to support the claim that the mean is less than 16.2 in smokers.\r<BR>\n" );
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document.write( "Can make a Type I error, of rejecting the Ho given that it might be true, although the probability is small (0.0038) </SPAN>\n" );
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