In statistics, an entire group of people or things is called a **population** or **universe**. A population can be **infinite** or **finite**. Examples of *finite* populations include the number of airplanes owned by an airline, or the potential consumers in a target market. Examples of* infinite* populations include the number of products manufactured by a company that plans to be in business forever, or the growth of bacteria given ample resources to grow.

A small part of the entire group chosen for study is called a **sample**. For example, in a study of the heights of students at a particular college, the entire student body is the *population*. The population is *finite* because it’s not growing in any way as the study is conducted. Instead of studying every student in the population, we may choose to work with a *sample* of only 100 students.

**Frequency Distributions**

Data that has not been organized in any way is called **raw data**. Data that has been sorted into *ascending* or *descending* order are called an **array**. The **range** of the data is the difference between the largest and the smallest number in that *array*.

Question:Arrange the following in ascending order; find its range.56.2, 72.8, 58.3, 56.9, 67.5

Solution:Largest value: 72.8

Smallest value: 56.2

Range: 72.8 – 56.2 = 16.6

Ascending order means smallest to largest: 56.2 → 56.9 → 58.3 → 67.5 → 72.8