Thursday, April 7, 2011

MEAN Average


  
Basically , MEAN is a type of average that is calculated by adding up all the numbers and dividing it by the amount of numbers .

For example, there are a set of 3 numbers, 12, 52 and 98.
To find the average, you simply have to add up all the three numbers/data.
12+52+98=162
After that, you have to divide that total by the number of numbers added up, which is 3.
So, you have to divide 162 by 3.
162÷3=54
Therefore, 54 is the average of the three numbers.

Advantages of mean : Helps us find the most accurate average of the set of numbers compared to Mode & Median
Disadvantages of mean : Outliers can change the mean a lot , making it much lower or higher than it should have been.


Here is all the research we have done



                                                 Mean (Average)

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Bowen:
Mean:
What? Define.
Mean is the expected value of a number found through a set of numbers.
How?to calculate the process.
The sum of all the data divided by the number of pieces of data.
e.g. Find the average amount of money the two boys have if the 1st boy got 55 and the second boy got 67
The formula would be: 55+67
                                        2      =122/2=61
Why?Advantages and Disadvantages.
The advantage is that easy to understand and easy to calculate as the formula is very simple.The disadvantages that it can be used with numbers of extreme differences as the average would not be accurate.
e.g. Find the average amount of money the two boys have if the 1st boy got 10 and the second boy got 1000000000000000
so :(10+1000000000000000)/2=500000000000005, would not be accurate.



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DYLAN:
Mean

What? Define.
-It is the most common type of “averages” used in interpretating sets of data. Mean can also be defined as a number that “evens out” or “balances” data.

How to calculate its process?
-It can be calculated by adding up all the data,  and divided by the total number of numbers added up. To make it clearer, an example would be this:
For example, there are a set of 3 numbers, 12, 52 and 98.
To find the average, you simply have to add up all the three numbers/data.
12+52+98=162
After that, you have to divide that total by the number of numbers added up, which is 3.
So, you have to divide 162 by 3.
162÷3=54
Therefore, 54 is the average of the three numbers.Apply this same concept whenever you want to find mean.

What are its advantages and disadvantages?
-If your sample is "normal", meaning if you do not have extreme scores, either very high or low, the average is good. If you have a normal distribution the mean is good. In a normal distribution, the mean is the same as median, which is also the same as mode.

-If you have extreme scores it will distort your average number, and therefore it will be better to use the median (number where 50% of the scores are above and 50% of the scores are below the median). The mode calculates the most frequently occurring score.

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Praveen:
Mean

One of the ways to calculate average is MEAN .It is taught to primary school students.MEAN can be calculated by  "Adding up all the numbers and dividing it by the  Amount of numbers "


This is a very common way to calculate average .

For example, the mean of six values: 34, 27, 45, 55, 22, 34 is

                                     34 + 27 + 45 + 55 + 22 + 34

                        
                                    6(The number of numbers on top)

= 217 / 6
36.167

Advantages of mean : Helps us find the most accurate average of the set of numbers compared to Mode & Median
Disadvantages of mean : Outliers can change the mean a lot , making it much lower or higher than it should have been.



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Harindrar 
Mean is a method of calculating averages and is a method we are familiar of  as we frequently used it in primary school. The process of using mean is actually evenly distributing the numbers given. To put it simply mean can be calculated by:
(total value of the items) divided by (total number items)
imagine the following numbers:
1,2,3
if you want to find their mean you must(according to my previous explantion) first find their total value which is:
1+2+3=6
and then you need to find the total number of items which if you count is:
3
then you divide them both:
6/3=2
actually if you paid attention i said before that“The process of using mean is actually evenly distributing the numbers given.” and if you noticed the three numbers were evenly distrubuted to get the number three and if you evenly distribute those numbers you would be:
taking 1 from 3 to make it 2 and giving the 1 taken from the 3 to the number 1 to make it 2 as well..
but this is more complicated so the first explanation is better...

there are also some disadvantages of using mean unlike median(arranging all the observations from lowest value to highest value and picking the middle one) and mode(value that occurs most frequently) the mean does not work very well in situations like these:
1,2,300000
in the above situation there is an outstanding value that will affect the whole process of calculation....therefore mean will not work for that...

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Yan Feng Explanation: Mean is a method of calculating averages of a set of data.We can calculate Mean by using the (total amount of value from the numbers) dividing it by (total number of items).Imagine Bob weighs 29kg while Tom weighs 68kg, if you want to find the mean of the their total weight. You must add 29 and 68 and take the result and divide it by two since there are only Bob and Tom.So...
29+68=97
97÷2=48.5
So the mean of their weight is 48.5
The advantages of a mean is that it is easy to use and it is good at finding low averages where the numbers in your set of data do not have extreme differences.But if the numbers have Extreme Differences because the results will not be THAT accurate and it will also distort the average number.




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Darshan explanation:Mean can be define as the total of all numbers combined divided by the number of numbers given in the data.It is like average.To calculate it you need to take the total amount from the numbers divided number of numbers given.For example:There are 3 boys.John weighs 50kg,Bob weighs 60kg and Tom weighs 70 kg.Find the mean of their weight.So you take the total of their weight.
50kg+60kg+70kg=180kg
Now you divide by the number of boys there are.So
180kg÷3=60kg
So the mean of the 3 boys is 60kg.
The advantage of using MEAN is because it is easier to use and it is more accurate if the numbers are around the same number.However if the number are like 1 and 1000000.The data would not be accurate as it would mean that both 500000.5 each.However actually one is getting 1 and 1000000.So this will serve as a disadvantage.
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Shiying

In statistics, the mean is the mathematical average of a set of numbers. The average is calculated by adding up two or more scores and dividing the total by the number of scores.

The mean is the math average of a set of numbers.

Mean is calculated by calculating two or more of the scores and dividing it by the total number of scores.

Advantages: Finds the most accurate average of the set of numbers.
Disadvantages: Outliers can change the mean a lot... making it much lower/higher than it should be.

Advantages: It finds the most accurate average of the set of  numbers
Disadvantages: If there is an outlier in the set of numbers, mean cannot be used in this case as the difference between the numbers are too large, hence affecting the average.

1 comment:

  1. Why we use mean:To even out/balance a set of data.

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