How do you find p-values?

Answer 1

Using a statistical software package is great!

Otherwise, it HIGHLY depends on what you are finding the P-value for! This information would have been helpful.

If you are looking for p-values based on something using the normal distribution, this is simple. Calculate the z-score of your observed result (be it individual observation if the population is normally distributed, or sample observation). Then do a reverse lookup in a z table to find the corresponding 4 digit decimal.

If using a symmetric z table, you will need to subtract that decimal from .5, then double the result if using a 2-tail test. Don't double if a 1-tail test.

If using a cumulative z table, you will need to look up the result for the negative signed z-score; double your result if 2-tailed, don't double if one-tailed.

Next time, be more specific, and the answer will be!