The first and last use error bars computed from statistical measures from
the data - you would need a course in elementary stats to understand this.
The percentage on use a percentage for the error bars. Example you want to
plot with 10% error bars. Say one value is 60 then the error bars will go
from ( 60 minus 10% of 60 ) to (60 plus 10% of 60)

60 minus 10% of 60 = 60 - (10/100)*60 = 60 - 6 = 54
60 plus 10% of 60 = 60 + (10/100)*60 = 6 +6 =66

best wishes
--
Bernard Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme


"Office_user" wrote in message
...
I need a simple explanation for the function of the following error bars
types:

- Error Bars with Standard Error
- Error Bars with Percentage
- Error Bars with Standard Deviation

Thanks in advance