Question 177923This question is from textbook Applied Statistics
: I am having the hardest time trying to solve both of the below questions. Can you please help guide me on the right track with this, perhaps get me started with the first step. Any help is greatly appreciated. Thanks!
1- You want to prove that a population mean is not 7. Data is ratio and a large sample size will be used (n = 225). When the sample is done the sample mean is computed to be 7.2 and the sample standard deviation is 1.5. Test the hypothesis using an alpha of 5%. Use formal hypothesis testing and compute the p-value.
2- An associate asks for your help in deciphering the following Anova table, indicating that a test of means was performed on the average age of people at three different locations. Unfortunately the person leaves before you can get any further explanation or detail, but you know the results must be presented before senior staff within twenty minutes!
Use the formal 5-step hypothesis testing model to describe the test, the results and interpret the results in conversational English.
ANOVA
Source of Variation--- SS----- df----- MS----- F------ P-value F crit
Between Groups------- 700.0--- 2------ 350.0-- 4.00--- 0.0288 3.32
Within Groups-------- 2625.0-- 30----- 87.5
Total------------------3325.0-- 32
**The above is suppose to be a table.
This question is from textbook Applied Statistics
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1- You want to prove that a population mean is not 7. Data is ratio and a large sample size will be used (n = 225). When the sample is done the sample mean is computed to be 7.2 and the sample standard deviation is 1.5. Test the hypothesis using an alpha of 5%. Use formal hypothesis testing and compute the p-value.
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Ho: u = 7
Ha: u is not equal to 7
Critical value for 2-tail test and alpha = 5%: +/-1.96
Test Statistic: z(7.2) = (7.2-7)/[1.5/sqrt(225)] = 2
p-value = 2*P(z>2) = 2*0.02275.. = 0.0455..
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Conclusion: Sinde the p-value is less than 5%, reject Ho.
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P.S. I assume you were able to figure out #2.
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Cheers,
Stan H.
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Comment on your #2:
To see an analysis of EXCEL ANOVA output use Google
with that search string.
Or just go to:
http://org.elon.edu/econ/sac/anova.htm
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Cheers,
Stan H.
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