Question

If 1,000 students take a test that has a mean of 40 minutes, a standard deviation of 8 minutes, and is normally distributed, how many would you expect would finish in between 24 and 48 minutes?

Answer 1

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

Answer 2

I get .8186 between 24 and 48
so
about 819 out of 1000