Question 265581: Given the following situation, how would you use Megastat to test whether the two population means are different? Please identify the two populations, outline the process for the test and, if necessary, including the output from Megastat to explain your approach. What assumption do you need to check to make sure that the analysis is valid?
"A random sample of 100 pencils produced by assembly line A was inspected in a pencil factory. It was found that the average length is 13.5 cm and the sample standard deviation is 1 cm Another random sample of 80 pencils from assembly line B in the same factory give an average length of 14.26 cm and sample standard deviation of 1.2 cm. Can we conclude that the average length of pencils produced by the two assembly lines are different at the 5% level of significance?"
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! "A random sample of 100 pencils produced by assembly line A was inspected in a pencil factory. It was found that the average length is 13.5 cm and the sample standard deviation is 1 cm.
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Another random sample of 80 pencils from assembly line B in the same factory give an average length of 14.26 cm and sample standard deviation of 1.2 cm.
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Can we conclude that the average length of pencils produced by the two assembly lines are different at the 5% level of significance?"
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Ho: u(A)-u(B) = 0
Ha: u(A)-u(B) is not equal to 0
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I ran a 2Sample Ttest and got the following:
test statistic: t = -4.5419
p-value = 0.00001122
df = 153.38
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Conclusion: Since the p-value is less than 5%, reject Ho.
The pencils produced by the lines are different at the 5% level of significance.
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Cheers,
Stan H.
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