Numeracy

Averages: Mean, Median, and Mode





1. Mean

  • Definition: The sum of all values divided by the number of values.
  • Formula:
    [
    {Mean} = \frac{{Sum of all values}} / {{Number of values}}
    ]
  • Example:
  • Prices of loaves of bread: $1, $1.20, $1.10.
  • Total: (1 + 1.20 + 1.10 = 3.30).
  • Mean = (3.30 \div 3 = $1.10).

Key Uses: Finding an average value for a dataset, predicting trends, or comparing groups.


2. Median

  • Definition: The middle value in a ranked (sorted) dataset.
  • Steps:
  • Arrange values in ascending order.
  • Identify the middle value:

    • For an odd number of values: Single middle value.
    • For an even number of values: Average of the two middle values.
  • Example 1 (Odd dataset):
    Dataset: 6, 13, 67, 45, 2.
    Ranked: 2, 6, 13, 45, 67.
    Median = 13.

  • Example 2 (Even dataset):
    Dataset: 6, 13, 67, 45, 2, 7.
    Ranked: 2, 6, 7, 13, 45, 67.
    Median = ((7 + 13) \div 2 = 10).

Key Uses: Handling skewed data to represent the "middle" value.


3. Mode

  • Definition: The most frequently occurring value(s) in a dataset.
  • Steps:
  • Count the frequency of each value.
  • Identify the value(s) with the highest frequency.

  • Example 1 (Single mode):
    Balloon colors: 18 red, 12 blue, 24 orange, 25 purple, 21 green.
    Mode = Purple.

  • Example 2 (No clear mode):
    Speeds: 40, 34, 42, 38, 41, 50, 48, 49, 33, 47.

  • All values are unique No mode.
  • Grouped Mode: Create categories:
    • 30–32: 0, 33–35: 2, 36–38: 1, 39–41: 2, 42–44: 1, 45–47: 1, 48–50: 3.
    • Mode = Category 48–50 Midpoint: 49.

Key Uses: Identifying the most common occurrences, such as customer preferences or frequently observed trends.


Comparison of Mean, Median, and Mode

| Measure | Best for | Limitations |
|-----------------|---------------------------------------------------|------------------------------------------------|
| Mean | Evenly distributed data, detailed comparisons. | Affected by extreme values (outliers). |
| Median | Skewed or non-symmetrical data. | May not fully represent all data points. |
| Mode | Categorical data or frequent occurrences. | Less useful with no repetition or multiple modes. |


Practical Applications

  • Business: Calculate average sales or revenue trends.
  • Education: Analyze student performance using mean and median scores.
  • Science: Use mode to study repeated observations in experiments.
  • Daily Life: Plan budgets or predict future expenses based on averages.

By understanding these measures, you can better interpret and analyze data to make informed decisions!


If you liked this, consider supporting us by checking out Tiny Skills - 250+ Top Work & Personal Skills Made Easy