document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=867794>Question 867794</A>: <I><SPAN STYLE=\"word-break: break-all;\"> From a population which can only be approximated by a normal distribution, a sample of [n=25 elements] is selected and the standard deviation of the sample is computed. For the interval estimation of the population mean, the proper distribution to use is the: <BR>\n" );
document.write( "a. Normal distribution <BR>\n" );
document.write( "b. T distribution <BR>\n" );
document.write( "c. T distribution with 25 degrees of freedom <BR>\n" );
document.write( "d. T distribution with 24 degrees of freedom <BR>\n" );
document.write( "e. None of the above<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 #523229 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=523229\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Some books vary (since it's not a hard fast rule), but in most cases I've seen that you use the t distribution if you don't know the population standard deviation and n <= 30. \r<BR>\n" );
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document.write( "Since n <= 30 is true and we don't know population standard deviation, we use the t distribution.\r<BR>\n" );
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document.write( "The degrees of freedom would be n-1 = 25-1 = 24. \r<BR>\n" );
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document.write( "So the answer is <font color=\"red\">d. T distribution with 24 degrees of freedom </font> </SPAN>\n" );
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