Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**tina123****Member**- Registered: 2012-04-29
- Posts: 83

What does mean by mean?

What is the actual meaning of mean?

Let say you have 10 points like this

9, 5 , 8,10,8,7,11,8,4,6,9,11,4

Where would be the mean?

another example

9, 5 , 8,10,8,7,11,8,4,178,9,11,20

Kindly, tell where would be the mean?

Can we say that mean value represents the all number of values?

or we will say that mean is the average of the nearest number?

like in this example

9, 5 , 8,10,8,7,11,8,4,6,9,11,4

mean would near to these values

like in this example,.

9, 5 , 8,10,8,7,11,8,4,178,9,11,20

mean would be near the values but would not go to the so different values with others . like 20 and 178..i meant outlair.

Can we say that mean represent the cluster?

Can we say that mean represent the cluster?

Mean is also called centro-id of points. Right ,

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,815

Hi tina123;

The mean of the first one is 100 / 13.

The second group of data has a mean of 288 / 13.

The mean is just the average of all the numbers.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

**Online**

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,767

hi tina123

The diagram below shows one way to think about the mean.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,767

and this diagram shows a centroid G

There is a weightless beam pivoted at one end, A.

There are three weights on the beam; 4 Kg at a distance 2 units from A, 3 Kg at a distance 4 units from A, and 3 Kg at a distance 6 units from A.

The total weight is 10 Kg.

The centroid is the point on the beam at which 10 Kg would give the same turning moment.

(note: turning moment is weight x distance )

moments about A: 4 x 2 + 3 x 4 + 3 x 6 = 8 + 12 + 18 = 38.

OR : total x AG => AG = 38/10 = 3.8

Bob

ps. Don't know what to do for 'cluster'.

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline