15, What z-score value separates the highest 10% of the scores in a normal distribution from...

What z-score value separates the highest 10% of the scores in a normal distribution from the lowest 90%?

a. z=1.28

d. z=0.25

c. z=-1.28

d. z=-0.25

Expert Solution

The Z-score which differentiates the highest 10% from the lower 90% has to have a score "c" such that:

P(X<c) = .90

We look up the Z tables to get the following as Z score:

so, c = 1.282

Hence, the answer is a. Z = 1.28

milcah answered 2 years ago

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