document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1174739>Question 1174739</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve this:\r<BR>\n" );
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document.write( "It has been known in the past that the average number of children of<BR>\n" );
document.write( "a Filipino family is 6. A random sample of 25 families were selected and<BR>\n" );
document.write( "found to have an average of 3 children with a standard deviation of 1<BR>\n" );
document.write( "child. Can we say that the number of children of a Filipino family has<BR>\n" );
document.write( "gone lower? \r<BR>\n" );
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document.write( "Thank you! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #800225 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=800225\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> it sure sounds like it.\r<BR>\n" );
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document.write( "let's see what the statistical analysis says.\r<BR>\n" );
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document.write( "sample size is 25<BR>\n" );
document.write( "average is 3 children per family.<BR>\n" );
document.write( "standard deviation is 1 child.\r<BR>\n" );
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document.write( "since the standard deviation is from the sample rather than the population, then the t-score analysis is considered.\r<BR>\n" );
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document.write( "the standard error is equal to the sample standard deviation divided by the square root of the sample size.\r<BR>\n" );
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document.write( "that makes the standard error equal to 1/sqrt(25) = 1/5 = .2.\r<BR>\n" );
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document.write( "the t-score is equal to (x - m) / s\r<BR>\n" );
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document.write( "x is the raw score from the sample<BR>\n" );
document.write( "m is the assumed mean from the population.<BR>\n" );
document.write( "s is the standard error.\r<BR>\n" );
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document.write( "the standard error is the standard deviation of the distribution of sample means.\r<BR>\n" );
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document.write( "the t-score is equal to (3 - 6) / .2 = -3/.2 = -15.\r<BR>\n" );
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document.write( "at two-tailed 99% confidence interval, the critical t-score with 24 degrees of freedom (sample size minus 1 = degrees of freedom) would be plus or minus 2.797.\r<BR>\n" );
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document.write( "a t-score of -15 with 24 degrees of freedom is well beyond the left side critical t-score of-2.797 with 24 degrees of freedom.\r<BR>\n" );
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document.write( "it appears that there is overwhelming evidence that the average number of children in a filipino family has gone lower.\r<BR>\n" );
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document.write( "it's pretty safe to say that it has.\r<BR>\n" );
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document.write( "here's the critical t-score table that i used.\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF= \"https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf\" target = \"_blank\">https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf</a>\r<BR>\n" );
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document.write( " </SPAN>\n" );
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