Mean, Median, Mode


TermDefinition
Mean The mean is the sum of all values divided by the number of values.
It is similar to average.
Median Median is literally the middle value. If you listed all the values in numerical order, the middle value is the median.
If there are two middle values, then the median is the average of these two middle values.
Mode Mode is the value that is most common in a set of data.
There can be more than one mode in a set of data.
Range Range measures the span of values in the data.
It is the difference between the largest and smallest values of the data.


Example 1: Bar graph


mean
median
mode
range
The data set is {3, 8, 10, 3}.

Mean:
3 + 8 + 10 + 3
4		 = 24
4		 = 6
Median:
Listing the data values in order, we get 3, 3, 8, 10.
The middle values are 3 and 8.
3 + 8
2		 = 11
2		 = 5.5
Mode:
The value 3 occurs the most in the data set.

Range:
The largest value in the data set is 10 and the smallest value in the data set is 3.
10 - 3 = 7


Example 2: Table - no mode


Weight in Pounds
LarryJodyAngelo
986979
  
mean
median
mode
range
The data set is {98, 69, 79}.

Mean:
98 + 69 + 79
3		 = 246
3		 = 82
Median:
Listing the data values in order, we get 69, 79, 98.
The middle value is 79.

Mode:
Each value only occurs once in the data set. There is no mode for this data set.

Range:
The largest value in the data set is 98 and the smallest value in the data set is 69.
98 - 69 = 29


Example 3: Multiple modes

4, 15, 6, 6, 4  
mean
median
mode
range
The data set is {4, 15, 6, 6, 4}.

Mode:
Both 4 and 6 occur twice in the data set. The modes are 4 and 6.

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