The number of nails of a given length is normally distributed with a mean length of 5 in. and a standard deviation of 0.03 in. In a bag containing 120 nails, how many nails are between 4.97 in. long and 5.03 in. long?

about 41 nails

about 82 nails

about 60 nails

about 57 nails

Respuesta :

z=(4.97-5)/.03=-1

z=(5.03-5)/.03=+1

area under normal curve between -1 and 1 is .683

120*.683=82.0 nails are between 4.97 in. long and 5.03 in. long.

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