What is the sum of the value of the data divided by the total number values and usually called as the average of data?

Though we commonly use the word average in everyday life when discussing the number that’s the most “typical” or that’s “in the middle” of a group of values, more precise terms are used in math and statistics. Namely, the words mean, median, and mode each represent a different calculation or interpretation of which value in a data set is the most common or most representative of the set as a whole.

In this article, we’ll answer these questions and more:

  • Is there a difference between mean and average?
  • What’s the difference between mean, median, and mode?
  • How do you find the mean, median, and mode?

⚡ Quick summary

You find the mean (informally called the average) by adding up all the numbers in a set and then dividing by how many values there are. When you arrange a set of values from smallest to largest, the median is the one in the middle. The mode is simply the value that occurs the most in the set.

mean vs. average

In math, the word mean refers to what’s informally called the average. They mean the same thing, but in the context of math and statistics, it’s better to use the word mean to distinguish from other things that might be casually referred to as “average” values in a general sense (meaning values that are the most representative or common within the set).

What is the mean, median, and mode?

The mean is the number you get by dividing the sum of a set of values by the number of values in the set.

In contrast, the median is the middle number in a set of values when those values are arranged from smallest to largest.

The mode of a set of values is the most frequently repeated value in the set.

To illustrate the difference, let’s look at a very simple example.

How to find the mean, median, and mode

Here’s an example set of seven values: 2, 3, 3, 4, 6, 8, 9.

To find the mean: add up all the values (2+3+3+4+6+8+9=35) and then divide that total by the number of values (7), resulting in a mean of 5. This is what most people are referring to when they refer to the average of some set of numbers.

To find the median: find the value that’s sequentially in the middle. In a set of seven numbers arranged in increasing value, the median is the fourth number (since there are three before and three after). In this set (2, 3, 3, 4, 6, 8, 9), the median is 4. When a set has an even number of values, the median is the mean of the two middle values (in other words, you find the median by adding the two middle numbers together and dividing by two).

To find the mode: simply look to see which value shows up the most. In the example set, the mode is 3, since it occurs twice and all the other values occur only once.

Of course, this set of values is very simple compared to data sets you’re likely to encounter in real life. In cases when there is too much data to look at all at once, there are often special tools (such as those used in spreadsheet software) that you can use to determine the mean, median, and mode.

Published on October 9, 2020 by Pritha Bhandari. Revised on May 22, 2022.

The mean (aka the arithmetic mean, different from the geometric mean) of a dataset is the sum of all values divided by the total number of values. It’s the most commonly used measure of central tendency and is often referred to as the “average.”

Mean formulas for populations and samples

In research, you often collect data from samples and perform inferential statistics to understand the population they came from.

The formulas for the sample mean and the population mean only differ in mathematical notation. Population attributes use capital letters while sample attributes use lowercase letters.

Population mean

Population mean formulaExplanation
What is the sum of the value of the data divided by the total number values and usually called as the average of data?
  • What is the sum of the value of the data divided by the total number values and usually called as the average of data?
    = population mean
  • What is the sum of the value of the data divided by the total number values and usually called as the average of data?
     = sum of each value in the population
  • What is the sum of the value of the data divided by the total number values and usually called as the average of data?
    = number of values in the population

    The population mean can also be denoted as μ.

    Sample mean

    Sample mean formulaExplanation
    What is the sum of the value of the data divided by the total number values and usually called as the average of data?
    • What is the sum of the value of the data divided by the total number values and usually called as the average of data?
      = sample mean
    • What is the sum of the value of the data divided by the total number values and usually called as the average of data?
       = sum of each value in the sample
    • What is the sum of the value of the data divided by the total number values and usually called as the average of data?
      = number of values in the population

        The sample mean is also referred to as M.

        Steps for calculating the mean

        There are two steps for calculating the mean:

        1. Add up all the values in the data set.
        2. Divide this number by the number of values.

        We’ll walk through these steps with a sample data set.

        Let’s say you want to find the average amount people spend on a restaurant meal in your neighborhood. You ask a sample of 8 neighbors how much they spent the last time they went out for dinner, and find the mean cost.

        Data set
        Cost of dinner for two (USD)42 13 31 87 24 58 76 69

        Step 1: Find the sum of the values by adding them all up

        Because we’re working with a sample, we use the sample formula.

        FormulaCalculation
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
         42 + 13 + 31 + 87 + 24 + 58 + 76 + 69 = 400

        Step 2: Divide the sum by the number of values

        In the formula, n is the number of values in your data set. Our data set has 8 values.

        FormulaCalculation
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        = 8
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        = 400
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        = 400
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        8 = 50

        The mean tells us that in our sample, participants spent an average of 50 USD on their restaurant bill.

        Outlier effect on the mean

        Outliers are extreme values that differ from most values in the data set. Because all values are used in the calculation of the mean, an outlier can have a dramatic effect on the mean by pulling the mean away from the majority of the values.

        Let’s see what happens to the mean when we add an outlier to our data set.

        Data set
        Cost of dinner for two (USD)42 13 31 87 24 58 76 69 230

        Step 1: Find the sum of the values by adding them all up

        FormulaCalculation
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        42 + 13 + 31 + 87 + 24 + 58 + 76 + 69 + 230 = 630

        Step 2: Divide the sum by the number of values

        FormulaCalculation
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        = 9
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        = 630
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        = 630
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        9 = 70

        As we can see, adding just one outlier to our data set raised the mean by 20 USD. In this case, a different measure of central tendency, like the median, would be more appropriate.

        When can you use the mean, median or mode?

        The mean is the most widely used measure of central tendency because it uses all values in its calculation. The best measure of central tendency depends on your type of variable and the shape of your distribution.

        Type of variable

        The mean can only be calculated for quantitative variables (e.g., height), and it can’t be found for categorical variables (e.g., gender).

        In categorical variables, data is placed into groupings without exact numerical values, so the mean cannot be calculated. For categorical variables, the mode is the best measure of central tendency because it tells you the most common characteristic or popular choice for your sample.

        But for continuous or discrete variables, you have exact numerical values. With these, you can easily calculate the mean or median.

        Distribution shape

        The mean is best for data sets with normal distributions. In a normal distribution, data is symmetrically distributed with no skew. Most values cluster around a central region, with values tapering off as they go further away from the center.

        The mean, mode and median are exactly the same in a normal distribution.

        What is the sum of the value of the data divided by the total number values and usually called as the average of data?

        In skewed distributions, more values fall on one side of the center than the other, and the mean, median and mode all differ from each other. One side has a more spread out and longer tail with fewer scores at one end than the other.

        What is the sum of the value of the data divided by the total number values and usually called as the average of data?
        What is the sum of the value of the data divided by the total number values and usually called as the average of data?

        For skewed distributions and distributions with outliers, the mean is easily influenced by extreme values and may not accurately represent the central tendency. The median is a better measure for these distributions as it takes a value from the middle of the distribution.

        Alternatively, you can systematically review and remove outliers from your dataset in the data cleansing process.

        Frequently asked questions about the mean

        How do I find the mean?

        You can find the mean, or average, of a data set in two simple steps:

        • Find the sum of the values by adding them all up.
        • Divide the sum by the number of values in the data set.

        This method is the same whether you are dealing with sample or population data or positive or negative numbers.

        What are the different types of means?

        The arithmetic mean is the most commonly used mean. It’s often simply called the mean or the average. But there are some other types of means you can calculate depending on your research purposes:

        • Weighted mean: some values contribute more to the mean than others.
        • Geometric mean: values are multiplied rather than summed up.
        • Harmonic mean: reciprocals of values are used instead of the values themselves.

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        What is the sum of the data values divided by the number of data values in the set this is also called the average?

        The arithmetic mean is the sum of all of the data points divided by the number of data points.

        What is the sum of the values divided by the total number of values?

        MEAN-the sum of a set of numbers divided by the number of items in the set, also referred to as the average. MEDIAN- with a list of numbers that are arranged in numerical order, the median is the middle number. If there are two middle numbers, the median is the average of the two middle numbers.

        What is the sum of the data values?

        A "sum" is the sum of all the data (the observations) in a dataset. Once again, we're using very simple math here. Just add up all the numbers below from a dataset of childhood weights (you can use a calculator if you prefer).

        What is the average of the data?

        The average is the sum of the data divided by the number of data points. The mode of the data is equal to the most frequently occurring data point. In some instances when all the data point values are equal, the average is equal to the mode.

        Is median same as average?

        The average is calculated by adding up all of the individual values and dividing this total by the number of observations. The median is calculated by taking the “middle” value, the value for which half of the observations are larger and half are smaller.

        What is calculated by adding all the data points and dividing the total by the number of data points?

        The arithmetic mean of a dataset (which is different from the geometric mean) is the sum of all values divided by the total number of values. It's the most commonly used measure of central tendency because all values are used in the calculation. There are 5 values in the dataset, so n = 5.