This is one version of a z table. It gives the probability that a standard normal random variable, Z, will exceed 0 by no more than a given amount, z. Equivalently, it gives the probability of any normal random variable exceeding its mean by no more than a given number of standard deviations. See Z-score for more information. To look up the probability of Z being between 0 and 1.96, for example, look in the row for 1.9 and the column for 0.06; the probability is 0.4750.