CHECK MY MATH PLEASE

Question

Assuming a normal distribution, what is the z-score associated with the 90th percentile? =1.2816

 

 Examine the intelligence quotient, or IQ, as it is defined by the formula: “intelligence quotient = 100 * (mental age/chronological age)” What would be the IQ if a person’s chronological age equals their mental age? If I’m correct it will = 100

 

 

HOPEFULLY THIS IS CORRECT

Answer 1

use a z calculator on line or handheld or use z tables

by the empirical rule the 97.5th percentile is z=2

90th percentile is less than z=2,

z=1.282