Question 445106
Suppose that the average grade for all people who take this course in statistics is 83 with a standard deviation of 3.5.
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If your particular class has an average of 89, can you conclude that your class is better than average at the 90 percent confidence level?
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Label and describe each step of the hypothesis testing procedure, and be sure to specify whether this is a one-tailed or two-tailed test.
But with the sample size of 30.
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Ho: u <= 83
Ha: u > 83 (the question)
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This Ha implies the need for a right-tail test.
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If you conduct a Z-test:
Critical value = invNorm(0.9) = 1.2816
test stat: z(89) = (89-83)/[3.5/sqrt(30)] = 9.3900
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Conclusion: Since the test stat is in the reject interval,
reject Ho.
The test results support a positive answer to the question.
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Cheers,
Stan H.
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