Answer to Question #305679 in Statistics and Probability for pay

Question

In an achievement test, the mean score of normally distributed values is 70 and the standard deviation is 12. What is the percentage of students who got a score of 85 and above?

Answer 1

$$P(X\ge85)=1-P(X<85)$$

$$=1-P(Z<\dfrac{85-70}{12})=1-P(Z<1.25)$$

$$\approx0.10565$$

$10.565\%$