Wednesday, April 13, 2011

Median(kinda long but this is not a copy paste article)

Median What is it?
-It is the number that is in the middle of an order of numbers in ascending/descending order.

How do we do it?
(Odd numbers)
To find the median in an order of numbers, we must
-know how many numbers are there in a row
-the numbers must be in ascending/descending order.
then, we add one to the total amount of numbers and divide by two (x+1/2=y).
-the yth number in the number arrangement will be the median number.
eg.1,4,1,4,7,7,3,4,0, the arrangement will be 0,1,1,3,4,4,4,7,7. The total amount of numbers will be 9. Then we add one to 9 and divide by 2 which is equal to 5 (9+1/2=5), hence the median number is 4.

(Even numbers)
To find the median in an order of numbers, we must
-know how many numbers are there in a row
-the numbers must be in ascending/descending order. 
-divide the total numbers by two(x/2=y)
-count the yth number in the number arrangement 
-add the yth number and add the 1st number on the left and divide by two which would give the median number is the total amount of numbers is an even number ( if yth no. ->5 and the one on the left is 7 then, add 5 to 7 and divide by 2 which is 6 and 6 is the median number(5+7/2=6) (If the end number has a decimal point, the number with the decimal point is still the median number.).
The formula for odd number is x+1/2 and for even number is x/2+y(1st no. on the left)

Why and how it is used
It is not always used as finding the median number is finding the 'middle number' in a string of numbers.
Finding the median number is used when we are finding the 'middle number' in a string of numbers and is not the mean of a string of numbers.
eg. mean of 2,5,1,7 is 3.75
      median of 2,5,1,7 is 3.5

This is not a copy paste work.
Pey Ruo-Song

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