mean 80, standard dev 14: 80% of values above what value?

Standard deviation, mean, variance, z-scores, t-tests, etc.
rushange
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mean 80, standard dev 14: 80% of values above what value?

Postby rushange » Tue Jun 01, 2010 5:19 am

A normal distribution has a mean of 80 and a standard deviation of 14. Determine the value above which 80 percent of the values will occur.

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stapel_eliz
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Postby stapel_eliz » Tue Jun 01, 2010 12:02 pm

rushange wrote:A normal distribution has a mean of 80 and a standard deviation of 14. Determine the value above which 80 percent of the values will occur.

What is the formula for converting the mean and the deviation to standard normals? (Look up the formulas they gave you in the boox.)

What is the z-score for the top 20% of values? (Look up the value on the z-score table.)

What value does this convert back to? (Use the formula they gave you.)


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