SOLUTION: A study is conducted to estimate the mean completion time of a task to within 2 minutes 36 seconds of the population mean. Suppose completion time is normally distributed with a st
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Question 1187842: A study is conducted to estimate the mean completion time of a task to within 2 minutes 36 seconds of the population mean. Suppose completion time is normally distributed with a standard deviation of 7 minutes 54 seconds. What minimum sample size is required at the 96.6% confidence level?
You must use a critical z value rounded to two (2) decimal places.
Minimum sample size required = Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! error is 156 seconds
sd is 474 seconds
z(0.983)=2.12
error=z*s/sqrt(n)
156=2.12*474/sqrt(n)
sqrt(n)=2.12*474/156=6.44
n=41.49 round to 42
