document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=342479>Question 342479</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A normal population has a mean of 75 and a standard deviation of 5. You select a sample of 40. Compute the probability the sample mean is:	<BR>\n" );
document.write( "a. Less than 74.<BR>\n" );
document.write( "b. Between 74 and 76.<BR>\n" );
document.write( "c. Between 76 and 77.<BR>\n" );
document.write( "d. Greater than 77.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #245239 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=245239\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A normal population has a mean of 75 and a standard deviation of 5. <BR>\n" );
document.write( "You select a sample of 40. Compute the probability the sample mean is:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Note: The mean of the sample means is 75<BR>\n" );
document.write( "The std of the sample means is 5/sqrt(40) = 0.7906<BR>\n" );
document.write( "--------------------------- <BR>\n" );
document.write( "a. Less than 74.<BR>\n" );
document.write( "t(74) = (74-75)/0.7906 = -1.2649<BR>\n" );
document.write( "P(xbar < 74) = P(t < -1.2649 when df = 39) = 0.1067<BR>\n" );
document.write( "----------------------------------------------------------<BR>\n" );
document.write( "b. Between 74 and 76.<BR>\n" );
document.write( "t(76) = (76-75)/0.7906 = +1.2649<BR>\n" );
document.write( "P(74< xbar < 76) = P(-1.2649 < t < 1.2649 when df = 39) = 0.7866<BR>\n" );
document.write( "------<BR>\n" );
document.write( "c. Between 76 and 77.<BR>\n" );
document.write( "d. Greater than 77.<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Use the same procedure for \"c\" and for \"d\".<BR>\n" );
document.write( "================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );