Posted by Anonymous on .
Assume that the salaries of elementary school teachers in the U.S. are normally distributed with a mean of $37,000 and standard deviation of $3500. The cutoff salary for teachers in the bottom 12% is

help 
Reiny,
Working this kind of problem will require tables or some other form of "lookup".
Here is the perfect method to replace good ol' tables in back of textbooks
http://davidmlane.com/hyperstat/z_table.html
click on "value from area"
enter .12 in "area"
enter 37000 in "mean"
enter 3500 in SD
click on "below" and
lo and behold  cutoff salary is $32887