Question 740412: Test the claim that the mean time Americans spend watching TV per day is 4.4 hours at the 0.10 level of significance. A random sample of 80 people had a mean time of 2.225 hours viewing per day and a standard deviation of 1.088 hours.
I have a hard time determining whether to use a z test or t test. Here I think it is a z test because the sample is over 30.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Test the claim that thee mean time Americans spend watching TV per day is 4.4 hours at the 0.10 level of significance. A random sample of 80 people had a mean time of 2.225 hours viewing per day and a standard deviation of 1.088 hours.
I have a hard time determining whether to use a z test or t test. Here I think it is a z test because the sample is over 30.
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Some texts use a t-test for ALL means testing. Others use the t-test
only for samples <= 30. You'll have to check your text to see which
way to go, or do it both ways.
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Ho: u = 4.4(claim)
Ha: u # 4.40
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z(2.225) = (2.225-4.4)/1.088 = -1.9991
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p-value = 2*P(z < -1.9991) = 2*normalcdf(-100,-1.9991) = 0.04560
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Since the p-value is < 10%, reject Ho.
The test results do not support the claim.
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Cheers,
Stan H.
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