Full question:
Suppose SAT scores among students are normally distributed with a mean of 500 and a standard deviation of 100.
If a college says it admits only people with sat scores among the top 10%. how high a sat score does it take to be eligible?
Answer and explanation:
To find where SAT score of student falls in the test given mean and standard deviation of scores, we can calculate: x-500/100 where x is number of SAT score of students
A sat score in the top 10% region would have a score better than 90% of other SAT scores. Therefore 0.90 has a z score of 1.28
We use algebra to find the score to be eligible thus:
1.28=x-500/100
x-500=128
x=128+500
x=628
Therefore to be eligible, a student needs to score at least 628, and be in the top 10% of scores