SOLUTION: A previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. How many nickels does a coin counter manufacturer need to weigh so that s
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Question 1140115: A previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. How many nickels does a coin counter manufacturer need to weigh so that she can be 98% confident that her sample mean is within 25 milligrams of the true average weight of a nickel? Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! the error= z*sigma/sqrt(n)
so 25=2.33*150/sqrt(n)
25 sqrt(n)=349.5
sqrt(n)=13.98
n=195.44 or round to 196
