Question 701827
 the standard deviation is 3.18 seconds. 
(A) How many measurements should be made in order to be 98% certain that the maximum error of estimation will not exceed 2.0 seconds?
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Since E = z*s/sqrt(n), 
n = [z*s/E]^2
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Also, 98% confidence has a left tail of 1% and a right tail of 1%
-invNorm(0.01) = 2.3263
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Your Problem:
n = [2.3263*3.18/2]^2 = 14 when rounded up
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(B) What sample size is required for a maximum error of 1.0 seconds
n = [2.3263*3.18/1]^2 = 55 when rounded up
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Cheers,
Stan H.
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