\(\mathbb P(X>600)=\mathbb P\left(\dfrac{X-510}{85}>\dfrac{600-510}{85}\right)=\mathbb P(Z>1.059)\approx0.145\)
So approximately 14.5% of the scores are higher than 600. This means in a sample of 7500, one could expect to see \(0.145\times7500\approx10.86\) scores above 600.
