The combined math and verbal scores for students taking a national standardized examination for college admission, is normally distributed with a mean of 620 and a standard deviation of 220. If a college requires a student to be in the top 10 % of students taking this test, what is the minimum score that such a student can obtain and still qualify for admission at the college?

Question

The combined math and verbal scores for students taking a national standardized examination for college admission, is normally distributed with a mean of 620 and a standard deviation of 220. If a college requires a student to be in the top 10 % of students taking this test, what is the minimum score that such a student can obtain and still qualify for admission at the college? 
answer:(round to the nearest integer)

Reiny · Accepted Answer

using my favourite normal distribution graphing calculator (same as tables in back of text books)

http://davidmlane.com/hyperstat/z_table.html

click on
"value from an area"
then enter:
area = .9 (to be in top 10%, 90 must be "below" )
mean = 620
SD = 220
click on "below" and recalculate to get 901.98 or 902