Math Is Fun Forum

thomas1991

Guest

avrages

hey what are the 3 avrages and how do you work out each avrage please i totally forgot how and my pearents are hopeless

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: avrages

The three averages are mode, median and mean.

The mode of a set of numbers is the one that appears the most.
eg. 3, 5, 2, 4, 5, 3, 4, 3, 1

Here the mode is 3 because it appears the most. A set can have more than one mode - if there was another 4 in that list then the modes would be 3 and 4.
However, if all numbers appear the same amount of times (eg. 1, 2, 1, 2) then there is no mode.

The mode is the only average that can apply to things other than numbers.
The list "cat, dog, cat, hamster" has a mode of cat.

The median is the number that appears in the middle of a list when you put them in order.
The list above sorts into 1, 2, 3, 3, 3, 4, 4, 5, 5.
The number in the middle of this is the third 3, so 3 is the median here.
If the list has an even amount of numbers, then you go halfway between them.
The median of "3, 2, 7, 5" is 4, because that's halfway between 3 and 5.

The mean what most people think of when they say 'average'.
To find the mean of some numbers, you add them all together and then divide by however many there were.
Using the 1, 2, 3, 3, 3, 4, 4, 5, 5 list again, these numbers add up to 30.
There are 9 of them, so their mean is 30/9, or just above 3.

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Why did the vector cross the road?
It wanted to be normal.