SOLUTION: another questions i need help with:
In a random sample of 42 bolts, the mean length was 1.73 and the standard deviation was 0.06 inc. Use a normal or a t-distribution to constru
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Question 482441: another questions i need help with:
In a random sample of 42 bolts, the mean length was 1.73 and the standard deviation was 0.06 inc. Use a normal or a t-distribution to construct a 80% confidence interval for the mean.
Which distribution should be used to construct the 80% confidence interval?
A. Use a t-distributioin because the lengths are normally distrubted or o is known
B. Unse a normal distribution becasue the lengths are normally distributed and o is known
C. Use a normal distribution because n <_ 30.
D Use a t-distribution becasue n >_ 30
The 80% cofidence inteval is: Round to two decimal places as needed.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
In a random sample of 42 bolts, the mean length was 1.73 and the standard deviation was 0.06 inc.
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Use a normal or a t-distribution to construct a 80% confidence interval for the mean.
Which distribution should be used to construct the 80% confidence interval?
A. Use a t-distributioin because the lengths are normally distrubted or o is known
B. Use a normal distribution becasue the lengths are normally distributed
and sigma is known
C. Use a normal distribution because n <_ 30.
D Use a t-distribution becasue n >_ 30
The 80% cofidence inteval is: Round to two decimal places as needed.
-----
Answer: B
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Cheers,
Stan H.
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