Question 125134
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,
San H.




 (c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during manufacture.