To calculate p value from z score, you convert the standardized test statistic into a tail probability under the standard normal distribution. Even so, the z score tells you how many standard deviations an observed value lies from the mean expected under the null hypothesis. Also, the p value then measures how likely it would be to see a result at least that extreme if the null hypothesis were true. This relationship is central to hypothesis testing, because it lets you decide whether an observed effect is strong enough to reject a default assumption, or whether it could plausibly have arisen by random variation alone.
Introduction
In statistics, a z score is a standardized value that shows where an observation or sample statistic falls relative to a population mean, measured in standard deviations. When a z score is used in hypothesis testing, it usually represents
