It is positive when it lies above the mean. Remember, the z- score shows the number of standard deviations where the value lies below the mean. Whether it is above, below, or between the values of normal distribution. It is using to find the probability of statistic value. He was a Belgian astronomer and he linked this distribution and the z curve. This phenomenon was first considered by Lambert Quetelet. It reflects the area of the z curve on the graph for standard deviations.įor instance, standard distribution is using to show the variables of height, weight, and strength. Z table is simply a standard normal distribution of percentage from 1 to 100. So, he devised a bell-shaped figure on the graph that we usually call the z curve. A French mathematician Abraham de Moivre was interested in gambling and used to find probabilities of the coin flips.
Z table, an alphabetical term in the world of mathematics has its interesting origins from history.
