<PRE><B>Question 187065</B>
By measuring the amount of time it takes a component of a product to move from one workstation to the next, an engineer has estimate that the standard deviation is 4.5 seconds. 
a. How many measurements should be made in order to be 95% certain that the maximum error of estimation will not exceed 1 second?
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n = [z*s/E]^2
n = [1.96*4.5/1]^2 = 77.79..
Rounding up: n = 78
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b. What sample size is required for a maximum error of 2 seconds? 
n = [1.96*4.5/2]^2 = 19.45
Rounding up: n = 20
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Cheers
Stan H.
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