SOLUTION: a manufacture of tv tubes has for many years used a process giving a mean tube life of 4900 hrs and a standard deviation of 1200 hours. A new process is tried to see if it will in

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Question 235546: a manufacture of tv tubes has for many years used a process giving a mean tube life of 4900 hrs and a standard deviation of 1200 hours.
A new process is tried to see if it will increase the life significantly. A sample of 100 new tubes gave a mean life of 5000 hrs. Is the new process better than the old process at 1% level of significant? Construct hypotheses test it and interpret the result.

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
a manufacture of tv tubes has for many years used a process giving a mean tube life of 4900 hrs and a standard deviation of 1200 hours.
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A new process is tried to see if it will increase the life significantly.
A sample of 100 new tubes gave a mean life of 5000 hrs.
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Is the new process better than the old process at 1% level of significant? Construct hypotheses test it and interpret the result.
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Ho: u = 4900
Ha: u > 4900 (claim)
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Test statistic: t(5000) = (5000-4900)/[1200/Sqrt(100)] =1000/1200= 0.8333..
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p-value: P(t>0.8333 with df=99) = 0.2033
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Since the p-value is greater than 1% do not reject Ho.
The new process is not an improvement over the old process.
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Cheers,
Stan H.

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