This is the "bell-shaped" curve of the Standard Normal Distribution. It is a Normal Distribution with mean 0 and standard deviation 1. It shows you the percent of population:
A normal distribution is the bell-shaped frequency distribution curve of a continuous random variable. Visit BYJU’S to learn its formula, curve, table, standard deviation with solved examples.
In statistics, a standard normal table, also called the unit normal table or Z table, [1] is a mathematical table for the values of Φ, the cumulative distribution function of the normal distribution.
Here is the Standard Normal Distribution with percentages for every half of a standard deviation, and cumulative percentages: Example: Your score in a recent test was 0.5 standard deviations above the average, how many people scored lower than you did?
Entries represent Pr(Z ≤ z). The value of z to the first decimal is given in the left column. The second decimal is given in the top row. Entries provide the solution to Pr(t > tp) = p where t has a t distribution with the indicated degrees of freedom. p ) p where 2 has a chi-square distribution with the indicated degrees of freedom.