How do you use a z table?

A z table is used to calculate the probability of choosing something that is normally distributed. In order to use it, first a z score is needed. A z score is the number of standard distributions a value is away from the mean of the data. In order to find the z score, take the value of the datum, subtract the mean, then divide by the standard deviation. The result is a z score. Look up the z score on the table to find the probability of getting anything equal to or lesser than the value you chose.