# Probability values and z scores

1. May 12, 2010

### nellas

Can someone explain how to do this. I am totally stuck.
How do you find the z score of you are given the probability? I understand and can calculate the p value from the z score but cannot seem to do it in the opposite direction
Thanks

2. May 12, 2010

### hgfalling

Look up the probability in the "probability" column of the table and take the corresponding z-score. If you are using a software package, look for something like NORMINV, the inverse normal distribution function.