SOLUTION: QUESTION 6
A study of nickels showed that the the standard deviation of the weight of nickels is 300 milligrams. A coin counter manufacturer wishes to find the 95% confidence in
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-> SOLUTION: QUESTION 6
A study of nickels showed that the the standard deviation of the weight of nickels is 300 milligrams. A coin counter manufacturer wishes to find the 95% confidence in
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Question 1077162: QUESTION 6
A study of nickels showed that the the standard deviation of the weight of nickels is 300 milligrams. A coin counter manufacturer wishes to find the 95% confidence interval for the average weight of a nickel. How many nickels does he need to weigh to obtain an average accurate to within 25 milligrams?
A.
554
B.
782
C.
393
D.
144
You can put this solution on YOUR website! I will use z since the population sd can be assumed to be 300 mg
the interval has to be 25mg
the interval is z*s/sqrt (n)=25=1.96*300/sqrt(n)
25 sqrt (n)=588
square both sides
625 n=345744
n=553.19 or 554, rounding upward.
A.
