document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=320267>Question 320267</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The average yearly cost per household of owning a dog is $194.21. Suppose that we randomly select 30 households that own a dog. What is the probability that the sample mean for these 30 households is less than $187.00? Assume standard deviation = $27. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #229585 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=229585\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  The average yearly cost per household of owning a dog is $194.21. <BR>\n" );
document.write( "Suppose that we randomly select 30 households that own a dog. <BR>\n" );
document.write( "What is the probability that the sample mean for these 30 households <BR>\n" );
document.write( "is less than $187.00? <BR>\n" );
document.write( "Assume standard deviation = $27.<BR>\n" );
document.write( "-------------------------------------<BR>\n" );
document.write( "Sample mean: 187<BR>\n" );
document.write( "t(187)=(187-194.21)/[27/sqrt(30)] = -1.4626<BR>\n" );
document.write( "----\r<BR>\n" );
document.write( "\n" );
document.write( "P(x < 187) = P(t< -1.4626 when df=29) = tcdf(-1000,-1.4626,29) = 0.0772<BR>\n" );
document.write( "==================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );