The easiest way to find the probability from a z-score is to simply look up the probability that corresponds to the z-score in the z table.

This tutorial explains how to use the z table to find the following probabilities:

- The probability of a value being less than a certain z-score.
- The probability of a value being greater than a certain z-score.
- The probability of a value being between two certain z-scores.

Let’s jump in!

**Example 1: Probability Less Than a Certain Z-Score**

Suppose we would like to find the probability that a value in a given distribution has a z-score less than **z = 0.25**.

To find this probability, we need to look up 0.25 in the z-table:

The probability that a value in a given distribution has a z-score less than **z = 0.25** is approximately **0.5987**.

**Note**: This could also be written as **59.87%** in percentage terms.

**Example 2: Probability Greater Than a Certain Z-Score**

Suppose we would like to find the probability that a value in a given distribution has a z-score greater than **z = -0.5**.

To find this probability, we need to look up -0.5 in the z-table:

The probability that corresponds to a z-score of -0.5 is .3085.

However, since we want to know the probability that a value in a given distribution has a z-score *greater *than -0.5, we need to subtract this probability from 1.

Thus, the probability that a value in a given distribution has a z-score greater than -0.5 is: 1 – .3085 = **0.6915**.

**Example 3: Probability Between Two Z-Scores**

Suppose we would like to find the probability that a value in a given distribution has a z-score between **z = 0.4** and** z = 1**.

First, we will look up the value **0.4**** **in the z-table:

Then, we will look up the value **1**** **in the z-table:

Then we will subtract the smaller value from the larger value: **0.8413 – 0.6554 = 0.1859**.

Thus, the probability that a value in a given distribution has a z-score between z = 0.4 and z = 1 is approximately **0.1859**.

**Additional Resources**

The following tutorials provide additional information about z-scores:

5 Examples of Using Z-Scores in Real Life

How to Convert Z-Scores to Raw Scores

How to Find Z-Scores Given Area

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