Calculate mean, median, mode, and range

Mean, median, mode, and range are four different ways to understand a set of data. They help us find the 'average', the 'middle', the 'most frequent', and the 'spread' of the numbers. Let's dig into data!

Lesson 1

Concept

These four terms are key measures in statistics that help us summarize and understand data sets. **1. Mean (The Average)** The mean is what most people think of as the "average." * **How to find it:** 1. **Add** up all the numbers in the data set. 2. **Divide** by the count of how many numbers there are. * **Example:** For the set {2, 2, 4, 8} * Add: 2 + 2 + 4 + 8 = 16 * Divide: There are 4 numbers, so 16 ÷ 4 = 4. * The **mean** is 4. **2. Median (The Middle)** The median is the middle number in an **ordered** data set. * **How to find it:** 1. Put the numbers in order from least to greatest. 2. Find the number exactly in the middle. * If there are two middle numbers (in an even set), the median is the average of those two. * **Example:** For {2, 8, 4, 2} -> Order it first: {2, 2, 4, 8} * The two middle numbers are 2 and 4. * Find their average: (2 + 4) ÷ 2 = 3. * The **median** is 3. **3. Mode (The Most Frequent)** The mode is the number that appears most often in a data set. * **How to find it:** Look for the number that repeats the most. * **Example:** For {2, 2, 4, 8} * The number 2 appears twice, more than any other number. * The **mode** is 2. * A data set can have one mode, more than one mode, or no mode at all. **4. Range (The Spread)** The range tells you how spread out the data is. * **How to find it:** Subtract the smallest number from the largest number. * **Example:** For {2, 2, 4, 8} * Largest: 8 * Smallest: 2 * Subtract: 8 - 2 = 6. * The **range** is 6. **Key Idea:** * **Mean:** The "fair share" value. * **Median:** The "middle" value. * **Mode:** The "most popular" value. * **Range:** The "spread" of the values.

Try it

Practice: Calculate mean, median, mode, and range.