the score of an achievement test is given to 100000 students are normaly distributed with mean 500 and s.d 100.what should be the score of a student to place among him top 10% of all students

2 answers

from the z-score table

the top 10% of students have scores that are
... approximately 1.28 s.d. above the mean

500 + (100 * 1.28)
Answer please