SOLUTION: Birth weights at a local hospital have a normal distribution with a mean weight of 110 ounces and a standard deviation of 15 ounces. Using the unit normal table (and leaving off th

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Question 934918: Birth weights at a local hospital have a normal distribution with a mean weight of 110 ounces and a standard deviation of 15 ounces. Using the unit normal table (and leaving off the percentage signs):
a. What percent of infants have weights greater than 120 ounces?
b. What percent of infants have weights between 95 ounces and 125 ounces?
c. What birth weight value separates the lowest 2.5% of infants from the rest?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
mean = 110 oz, SD = 15 ounces, z+=+blue%28x+-+110%29%2Fblue%2815%29
....
P( x > 120) = P( z > 10/15) = normalcdf( 2/3, 100) = .2525
P(95 < x < 125) = P( -15/15 < z < 15/15) = normaldcdf(-1,1)= .6827
...
What birth weight value separates the lowest 2.5% of infants from the rest?
z = invNorm(.025) = -1.96
....
(15)(-1.96) + 110 = x = 80.6 oz
round as directed