The number of nails of a given length is normally distributed with a mean of 5.00 in. and a standard deviation of 0.03 in. Find the number of nails in a bag of 120 that are over 5.03 in. long.
A. about 40 nails
B. about 30 nails
C. about 20 nails
D. about 10 nails

Question

The number of nails of a given length is normally distributed with a mean of 5.00 in. and a standard deviation of 0.03 in. Find the number of nails in a bag of 120 that are over 5.03 in. long.
A. about 40 nails 
B. about 30 nails
C. about 20 nails
D. about 10 nails

anonymous · Answer

Can someone please help me, this is my last question and i have to get it right for me to pass.

kropot72 · Answer

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As shown in the above diagram of a normal distribution, approximately 16% of the data points are more than one standard deviation from the mean. Therefore if you take 16% of 120 you will have the approximate number of nails that are over 5.03 in. long.