Thursday, May 26, 2016

Mean, Median, Mode

Mean, Median, Mode
 
 
     Mean:
                      -- Also known as the average.  The mean is found by adding up all of the given data and
             dividing by the number of data entries.
                Example:
                             - the grade 10 math class recently had a mathematics test and the grades were as
                               follows:
 
                                       78
                                       66
                                       82                                  464 / 6 = 77.3
                                       89
                                       75                        Hence, 77.3 is the mean average of the class.
                                    + 74
                                      464


     Median:
                      -- The median is the middle number.  First you arrange the numbers in order from lowest
                to highest, then you find the middle number by crossing off the numbers until you reach the
                middle.
              Example:
                               - use the above data to find the median:
                                                66  74  75  78  82  89\
                            - as you can see we have two numbers, there is no middle number.  What do we do?
                   It is simple; we take the two middle numbers and find the average, ( or mean ).
                                                             75 + 78 = 153
                                                              153 / 2 = 76.5
                             Hence, the middle number is 76.5.
 
         Mode:
                        -- this is the number that occurs most often.
                 Example:
                                 - find the mode of the following data:
 
                                    78  56  68  92  84  76  74  56  68  66  78  72  66
                                    65  53  61  62  78  84  61  90  87  77  62  88  81
                                                   The mode is  78. 

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