What is mean?
Mean is the average of numbers.
Example:
3, 5, 6, 9, 8
Mean = all values/Total number of values
Mean = 3+5+6+9+8/5
Mean = 6.2
How to calculate the mean for data with frequencies?
Age  Frequency  Age * Frequency 
22  5  22 * 5 = 110 
33  2  33 * 2 = 66 
44  6  44 * 6 = 264 
66  4  66 * 4 = 264 
Total  17  704 
Mean = 704/ 17
Mean = 41
What is Median?
Median is the middle value among all values.
How to calculate the median for an odd number of values?
Example:
9, 8, 5, 6, 3
Arrange values in order
3, 5, 6, 8, 9
Median = 6
How to calculate median for an even number of values?
Example:
9, 8, 5, 6, 3, 4
Arrange values in order
3, 4, 5, 6, 8, 9
Add 2 middle values and calculate their mean.
Median = 5+6/2
Median = 5.5
What is Mode?
The mode is the most occurring value.
How to calculate mode?
Example:
3, 6, 6, 8, 9
Mode = 6 (because 6 is occurring 2 times and all other values occur only one time).
Why mean median and mode are equal in normal distribution?
The normal distribution is not dealing with skewed distributions. The mean, median, and mode are equal in normal distribution.
For example if we have a sample data, then Half of the population is greater and half is less than mean.
Next Tutorials with Similar Topics
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 Learn Mean, Median, Mode.
 Estimated Mean, Median, Mode – Click Here
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 Box Plot for Data – Click Here

Variance and standard deviation of data in data mining – Click Here Calculator – Click Here
 Data skewness – Click Here
 Correlation analysis of numerical data in Data Mining – Click Here
 Correlation analysis of Nominal data with ChiSquare Test in Data Mining – Click Here
 Data discretization and its techniques in data mining – Click Here
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Thank you very much, Santhiya
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