In statistics, there are three methods of calculation which are used to interpret the data, and they are the mode, mean and median. All of these are used to find the center of a data set, but each calculates it differently. The mean is also called the average and is the method used to find the center of numerical data. It is the average of all the numbers in the data set. Statistical average and mean are the same though people prefer to call it statistical average.
Average or mean is calculated by adding all the numbers and dividing them by the count of the numbers.
Example: You have to find the average of test scores in an academic year and you have scored 12, 20, 15 and 16 in four tests, to find the mean or average score you should add all the test scores and then divide the sum by the number of tests which is 4. The result is the mean.
(12+20+15+16) /4 = 15.75
Rounding it to the nearest number, the average test scores for this academic year will be 16.
How ToFind the mean of a negative number? Handling a negative number addition is similar to finding the difference of numbers. To learn how to find the mean of such numbers, consider the example of these numbers:
4, -5, 11, -1
The sum of the above numbers is 4-5+11-1 = 9
The above data set has 4 numbers, so the mean is 9/4 = 2.25
Applications of Mean
It is essential to learn to calculate the average or mean of a group of numbers. As a student, it will help you to calculate the average grade you have achieved in a series of test scores. Apart from that, there are several other applications and situations where you will use mean calculation. Like it helps the researchers, statisticians, economists, demographers, and biologists understand the research data better. Economists can calculate the average monthly expenditure of an American family and compare it with other countries to understand the current global economic situation. Alternatively, specific changes can be recommended to people based on the average temperature in a particular location and time and make better predictions and thus better decisions.
Advantages and Disadvantages of the Mean:
The mean or the average has advantages like:
- Help in encapsulating large chunks of data into a single value
- Show the variability around the single value within the original numbers.
- Though a mean is a handy tool, it also gives way to misleading information due to various reasons. Some of the examples where the averages are misleading are:
If there are 10 people in a room and one of them was pregnant. If the average is calculated, then it is 0.1% everyone was pregnant which does not give the right picture.
Take another example; Bill has grades of 4.0 in math, 3.0 in English, 3.0 in history and 4.0 in science. However, due to averaging the scores, he was termed as a 'B' student though he was good in math and science. All he needed was more work in history and English.
Take a note of the above steps as calculating the average and mean helps a great deal in daily life!