Steer me in the right direction??? please please!!!!

#1
ive been trying for a while and everytime i try to figure it out it seems like im lacking the sample size. Can someone please please please please please please please please please please please please at least steer me in the right direction for these two???

1.The score on the entrance exam at a well known, exclusive law school are normally distributed with a mean score of 200 and a standard deviation equal to 50. At what value should the lowest passing score be set if the school wishes only 2.5 percent of those taking the test to pass?


2.A machine is used to cut a metal automobile part to its desired length. The machine can be set so that the mean lengths of the part will be any value that is desired. The standard deviation of the lengths always runs at .02 inches. Where should the mean be set if want only .4 percent of the parts cut by the machine to be shorter than 15 inches long?
 

JohnM

TS Contributor
#2
These are applications of finding the area under the normal curve, and using the z-score formula z = (x - mean)/sd. You're not required to use sample size to figure these out.