How to find out the representive mark from a list?
 

My class has 30 students, their marks are shown below
100,97,96,93,88,85,84,77,76,71,
66,62,62,55,53,49,48,46,46,43,
43,43,43,43,35,33,31,31,31,13

I would like to determine the most representative mark for this class for
comparing with another class.

I think the functions - average, mode are not a very representative in this
case.
Does anyone have any suggestions on how to define the most representative
mark for this class?

Thank you in advance
Eric

How to find out the representive mark from a list?
 

Hi Eric,

Perhaps a Stem and Leaf graph may help.
I'll try one here, don't know if the formatting
will survive the trip through cyberspace.

10| 0
9| 7 6 3
8| 8 5 4
7| 7 6 1
6| 6 2 2
5| 5 3
4| 9 8 6 6 3 3 3 3 3
3| 5 3 1 1 1
2|
1| 3

You can see at a glance that the main body of your students
are in the 30 to 40 range. For ways to automate stem and
leaf graphs do a google search there are many different
approaches.

HTH
Martin


"Eric" wrote in message
...
My class has 30 students, their marks are shown below
100,97,96,93,88,85,84,77,76,71,
66,62,62,55,53,49,48,46,46,43,
43,43,43,43,35,33,31,31,31,13

I would like to determine the most representative mark for this class for
comparing with another class.

I think the functions - average, mode are not a very representative in
this
case.
Does anyone have any suggestions on how to define the most representative
mark for this class?

Thank you in advance
Eric

How to find out the representive mark from a list?
 

In what way do you consider that AVERAGE and MODE are "not a very
representative" in this case?

What do you want to do to make it more "representative"? If you don't want
to minimise the total difference, do you want a least squares fit, or do you
want to minimise
sigma[(x i-x rep)^n],
where you define your favourite value of n?

Another option is MEDIAN.
--
David Biddulph

"Eric" wrote in message
...
My class has 30 students, their marks are shown below
100,97,96,93,88,85,84,77,76,71,
66,62,62,55,53,49,48,46,46,43,
43,43,43,43,35,33,31,31,31,13

I would like to determine the most representative mark for this class for
comparing with another class.

I think the functions - average, mode are not a very representative in
this
case.
Does anyone have any suggestions on how to define the most representative
mark for this class?

Thank you in advance
Eric