Explanation:
First let's note* the given values:
Ζ = Χ - μ / σ
μ = 100;
σ = 15
Converting z score to a decimal P using the percentage-finding method you want.
a. Genius or near genius: IQ over 140
z > 40 / 15 = 2.6667 P(z > 2.6667) = .0038 3.8% of whole the population