Information is all around us. The number of students in a school, the amount of money an average citizen in a town earns, or the temperature for your vacation destination, are all numbers that are important in everyday life. But how can you take lots of information, such as the amount that all the citizens of a city earn, and make it meaningful? This is where statistics such as mean, median and mode become a valuable tool. Each has a specific way of looking at a group of data, and each one can give you a different insight into the way information behaves in the real world around you.
Mode Occurs Most
When looking at a set of information, the mode is simply the number that occurs most often in the set. Imagine that you live in a small town where most of the people are employed by a factory and earn minimum wage. One of the factory owners lives in the town and his salary is in the millions of dollars. If you use a measure like the average to try to compare salaries in the town as a whole, the owner's income would severely throw off the numbers. This is where the measure of mode can be useful in the real world. It tells you what most of the pieces of data are doing within a set of information.
Mean Is Average
The mean is commonly referred to as average, but it is not the only kind of average. The mean is often used in research, academics and in sports. When you watch a baseball game and you see the player's batting average, that number represents the total number of hits divided by the number of times at bat. In other words, that number is the mean. In school, the final grade you get in a course is usually a mean. This mean represents the total number of points you scored in the class divided by the number of possible points. This is the classic type of average – when your overall performance on many items is evaluated with a single number.
Median Is Another Kind of Average
Although the mean is the most common type of average, the median can also be used to express the average of a group. The median number in a group refers to the point where half the numbers are above the median and the other half are below it. You may hear about the median salary for a country or city. When the average income for a country is discussed, the median is most often used because it represents the middle of a group. Mean allows very high or very low numbers to sway the outcome but median is an excellent measure of the center of a group of data.
Choosing a Measure
As a consumer of information, it is important that you can make decisions about which measures are most useful. Just because you can use mean, median and mode in the real world doesn't mean that each measure applies to any situation. For example, if you wish to find the average grade on a test for your class but one student fell asleep and scored a 0, the mean would show a much lower average because of one low grade, while the median would show how the middle group of students scored. Using these measures in everyday life involves not only understanding the differences between them, but also which one is appropriate for a given situation.