SOLUTION: In a survey of women in the United States (ages 20-29), the mean height is 69.9 inches with a standard deviation 3.0 inches. a. What height represents the 95th percentile? b. W

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Question 456839: In a survey of women in the United States (ages 20-29), the mean height is 69.9 inches with a standard deviation 3.0 inches.
a. What height represents the 95th percentile?
b. What height represents the first quartile?
Answer by stanbon(75887) About Me  (Show Source):
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In a survey of women in the United States (ages 20-29), the mean height is 69.9 inches with a standard deviation 3.0 inches.
a. What height represents the 95th percentile?
Find the z-value with a left tail of 95%: z = 1.645
Use x = zs+u
x = 1.645*3+69.9 = 74.835 inches
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b. What height represents the first quartile?
Find the z-value with a left tail of 25%: z = -0.6745
x = -0.6745*3+69.9 = 67.877 inches
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Cheers,
Stan H.