Question 482955: Can someone please help me, I submitted a question and ot no answer.
A machine puts plastic into sheets that are 30 feet(360 inches)long. Assume that the population of lengths is normally distrubuted. Complete parts (a) and (b)
a) The company wants to estimate the mean length the machine is cutting the plastic within 0.25 inc. Determine the minimum sample sia required to construct a 95% confidence interval for the population mean. Assume the population standard deviation is 0.50 inch.
n=
b) Repeat part (a) using an error tolerance of 0.125 inc.
n=
Which error tolerane requires a larger sample size? Explain.
A The tolerance E= 0.125 inch requires a larger sample size. As error size increases, a larger sample must be taken to ensure the desired acuracy.
B. The tolerance E=0.25 inch requires a larger sample size. As erro size increases a larger sample must be taken to ensure the desired accuracy.
C. The tolerance E=0.25 inch requires a larger sample size. As error size
decreases, a larger sample must be taken to ensure the desired accuracy.
D. The tolerance E = 0.125 inch requires a larger sample size. As error size decreases, a larger sample must be taken to ensure the desired accuracy.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A machine puts plastic into sheets that are 30 feet(360 inches)long. Assume that the population of lengths is normally distrubuted.
Complete parts (a) and (b)
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a) The company wants to estimate the mean length the machine is cutting the plastic within 0.25 inc. Determine the minimum sample size required to construct a 95% confidence interval for the population mean. Assume the population standard deviation is 0.50 inch.
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n= [z*s/E]^2
n = [1.96*0.50/0.25]^2
n = 16 when rounded up
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b) Repeat part (a) using an error tolerance of 0.125 inc.
n= {1.96*0.50/0.125]^2
n = 62 when rounded up
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Which error tolerance requires a larger sample size? Explain.
A The tolerance E= 0.125 inch requires a larger sample size. As error size increases, a larger sample must be taken to ensure the desired acuracy.
B. The tolerance E=0.25 inch requires a larger sample size. As erro size increases a larger sample must be taken to ensure the desired accuracy.
C. The tolerance E=0.25 inch requires a larger sample size. As error size
decreases, a larger sample must be taken to ensure the desired accuracy.
D. The tolerance E = 0.125 inch requires a larger sample size. As error size decreases, a larger sample must be taken to ensure the desired accuracy.
0 solutions
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Answer: D ; Error size and sample size are indirectly related.
As the amount of allowed error decreases the sample size must rise.
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Cheers,
Stan H.
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