Question

Considering the IQ results, the school administrator is also planning to offer additional math courses to the top 20%. What should be the IQ score of the student to be qualified to take the additional math course?

Answer 1

$$P(X>x)=1-P(Z\le\dfrac{x-108}{10})=0.2$$

$$P(Z\le\dfrac{x-108}{10})=0.8$$

$$\dfrac{x-108}{10}=0.8416$$

$$x=116.4$$

The IQ score will be above 116.4