document.write( "Question 599532: it is thought that a normal population's mean is less than 75. To test this, a random sample of size 19 is drawn. THe sample mean is 73.5 and the sample standard deviation is 2.1. Find an approximate range for the p-value and state the conclusion. What would your range be if we had used a two-tail test? \n" ); document.write( "
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it is thought that a normal population's mean is less than 75. To test this, a random sample of size 19 is drawn. THe sample mean is 73.5 and the sample standard deviation is 2.1. Find an approximate range for the p-value and state the conclusion. What would your range be if we had used a two-tail test?
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\n" ); document.write( "Ho: u >= 75
\n" ); document.write( "Ha: u < 75 (claim)
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\n" ); document.write( "Test stat: t(73.5) = (73.5-75)/[2.1/sqrt(19)] = -3.1135
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\n" ); document.write( "p(value) = P(t < -3.1135 when df = 18) = 0.0030
\n" ); document.write( "Since the p-value is < 5%, reject Ho at the 5% significance level.
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\n" ); document.write( "If a 2-tail test, p-value = 2*0.0030 = 0.0060
\n" ); document.write( "We would still reject Ho.
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\n" ); document.write( "Note: The test results support the claim.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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