A middleschool principl has a 100 eighth grade students taking a standardized test with a mean equal to 400 with a standard deviation of 70. The...

A middleschool principl has a 100 eighth grade students taking a standardized test with a mean equal to 400 with a standard deviation of 70.  The scores are normally distributed.  What is the probability that the group of 100 students will have a mean score below 385?  Use te z-score table.