SOLUTION: I need help in my statistics class with exercises 8.46 and 8.62 in my textbook. The problems are listed below. 8.46 A random sample of 10 miniature Tootsie Rolls was taken fro

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Question 296061: I need help in my statistics class with exercises 8.46 and 8.62 in my textbook.
The problems are listed below.
8.46
A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on
a very accurate scale. The results in grams were
3.087 3.131 3.241 3.241 3.270 3.353 3.400 3.411 3.437 3.477
(a) Construct a 90 percent confidence interval for the true mean weight. (b) What sample size
would be necessary to estimate the true weight with an error of � 0.03 grams with 90 percent confidence?
(c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during
manufacture.

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were
3.087 3.131 3.241 3.241 3.270 3.353 3.400 3.411 3.437 3.477
(a) Construct a 90 percent confidence interval for the true mean weight.
A T-Interval is (3.2283,3.3813)
The sample mean is 3.304800 and E= 0.076500
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(b) What sample size would be necessary to estimate the true weight with an error of � 0.03 grams with 90 percent confidence?
n = [t*sigma/0.03]^2
n = [1.645*0.131989/0.03]^2
n = 7.237397^2
n = 52.3799
n= 53 rounding up
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Cheers,
Stan H.
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I'll leave (c) to you.
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(c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during manufacture.