The range shows how spread out the numbers are in a group. To find it, you subtract the smallest number from the biggest number. This gives you a quick idea of how varied the data is.

Steps to Calculate the Range:

1. Find the Highest Number:

   • For example, in the set {3, 7, 5, 2, 9}, the biggest number is $9$.

2. Find the Lowest Number:

   • In this same set, the smallest number is $2$.

3. Use the Range Formula:

   • The formula for finding the range is:
   $$\text{Range} = \text{Maximum} - \text{Minimum}$$
   • So, using the numbers we found:
   $$\text{Range} = 9 - 2 = 7$$

Why is the Range Important?

• Understanding Spread: The range helps us see how much difference there is between data points.
• Data Analysis: It is especially useful in areas like investments and research, where knowing how much things vary matters a lot.

Example Calculation:

Let's look at a set of test scores {48, 75, 65, 90, 56}. Here’s how to calculate the range:

• Maximum (biggest score): $90$
• Minimum (smallest score): $48$
• Now, we calculate the range:

$$\text{Range} = 90 - 48 = 42$$

So, the range of these test scores is $42$. This means there is a lot of variation in the scores.