Question 220936: Please show calculation to problem. Dullco Manufacturing claims that its akaline batteries last forty hours on average in a certain type of portable CD player. Tests on a random sample of 18 batteries showed a man battery life of 37.8 hours with a standard deviation of 5.4 hours. What is the test statistic? In a left-tailed test at a = .05 would we rejecting the claim, accepting the claim, either cause it is too close,or switch to a = .01 for a more powerful test.
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Dullco Manufacturing claims that its akaline batteries last forty hours on average in a certain type of portable CD player.
Tests on a random sample of 18 batteries showed a main battery life of 37.8 hours with a standard deviation of 5.4 hours.
Ho: u = 40 (claim)
H1: u < 40
What is the test statistic?
t(37.8) = (37.8-40)/[5.4/sqrt(18)] = -1.7285
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p-value = P(t<-1.7285 with 17 degrees of freedom) = 0.0510
In a left-tailed test at a = .05 would we rejecting the claim, accepting the claim, either cause it is too close,or switch to a = .01 for a more powerful test.
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Since the p-value is > 5%, fail to reject Ho.
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Cheers,
Stan H.
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