Median and Mode
The median is the middle value when data are sorted in order. The mode is the value that appears most often.
Median
The median is the middle value of an ordered data set. To find it:
- Arrange the values in ascending order.
- If there is an odd number of values, the median is the middle one. Its position is , where is the number of values.
- If there is an even number of values, the median is the mean of the two middle values.
For example, has 5 values. The median is the value, which is .
Mode
The mode is the value that occurs most frequently. A data set can have one mode, more than one mode, or no mode (if all values appear the same number of times).
For , the mode is because it appears twice while every other value appears once.
Watch it work
Question: Find the median and mode of .
Step 1: Sort the values: .
Step 2 (Median): There are 7 values. The middle position is . The 4th value is , so the median is 4.
Step 3 (Mode): The value 2 appears 3 times — more than any other. The mode is 2.
Have a go
Q1. Find the median of .
In order: . Middle (3rd) value.
Median =
Q2. Find the median of .
Even number of values. Median = .
Q3. Find the mode of .
Mode = (appears 3 times).
Q4. The data set has no repeated values. What is the mode?
There is no mode because no value appears more often than any other.
Q5. A data set has a median of 12 and a mode of 8. Is it possible for the mean to be 15? Explain.
Yes — the mean, median and mode can all be different values. A few large values could pull the mean above the median.