Whois & Analysis for z-table.com

A standard normal table, also called the unit normal table or Z table, is a mathematical table for the values of Φ, which are the values of the cumulative distribution function of the normal distribution.

It is used to find the probability that a statistic is observed below, above, or between values on the standard normal distribution, and by extension, any normal distribution.

Since probability tables cannot be printed for every normal distribution, as there are an infinite variety of normal distributions, it is common practice to convert a normal to a standard normal and then use the standard normal table to find probabilities.

In statistics, the standard score is the signed number of standard deviations by which the value of an observation or data point is above the mean value of what is being observed or measured.

Observed values above the mean have positive standard scores, while values below the mean have negative standard scores.

The standard score is a dimensionless quantity obtained by subtracting the population mean from an individual raw score and then dividing the difference by the population standard deviation.

This conversion process is called standardizing or normalizing (however, "normalizing" can refer to many types of ratios; see normalization for more).

In probability theory, the normal (or Gaussian) distribution is a very common continuous probability distribution.

Normal distributions are important in statistics and are often used in the natural and social sciences to represent real-valued random variables whose distributions are not known.

In mathematics, a negative number is a real number that is less than zero.

Negative numbers represent opposites.

If positive represents movement to the right, negative represents movement to the left.

If positive represents above sea level, then negative represents below level.

If positive represents a deposit, negative represents a withdrawal.

They are often used to represent the magnitude of a loss or deficiency.

A debt that is owed may be thought of as a negative asset, a decrease in some quantity may be thought of as a negative increase.

If a quantity may have either of two opposite senses, then one may choose to distinguish between those senses—perhaps arbitrarily—as positive and negative.

In the medical context of fighting a tumor, an expansion could be thought of as a negative shrinkage.

Negative numbers are used to describe values on a scale that goes below zero, such as the Celsius and Fahrenheit scales for temperature.

Mathematical tables are lists of numbers showing the results of calculation with varying arguments, before calculators were cheap and plentiful, people would use such tables to simplify and drastically speed up computation.

Tables of logarithms and trigonometric functions were common in math and science textbooks.

Specialized tables were published for applications such as astronomy, celestial navigation and statistics.