Question 387978
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Hi
*Note: {{{z = blue(x - mu)/blue(sigma)}}}   {{{mu}}} = 100, {{{sigma}}}= 15
Converting z score to a P decimal using the manner You choose to find percentage
a. Genius or near genius: IQ over 140 
  z > 40/15 = 2.6667 P(z > 2.6667) = .0038  3.8%  of the population
b. Very superior intelligence: IQ from 120 to 140  (z = 20/15 and z = 40/15)
 P( 1.333 < z <2.6667) = .0874    8.74% of the population
c. Average or normal intelligence: IQ from 90 to 109 (z = 9/15 and z = -10/15)
 ( - .6667 < z < .6) = .4733   47.33% of the population