If you know how to use built-in statistical functions on a calculator such as the TI-83 or 84, you can solve this problem with one press of the ENTER key on the calculator:
normalcdf(-100, 400, 504, 111) = 0.17 (answer)
Otherwise, find the z-score associated with 400:
400-504
z= ------------- , and the use a z-score table to find the area under the
111 standard normal curve to the left of this z value.
