How do i find class midpoints?
1 Answer
Jan 28, 2015
You just go halfway between the class limits.
BUT
Sometimes the class boundaries are a bit confusing.
Example: you work with age groups, like:
10-19
20-29
30-39
etc.
Then you would be tempted to use the midpoints:
14.5
24.5
34.5
as being halfway between 10 and 19 etc.
Untill you realise, that "10-19" actually means "10-19.99..."
(often written as 10-<20), then the midpoint should be 15.
In other cases, where 10 and 19 are always whole numbers (scores on a test or something like that) 14.5 would the right class midpoint.
Conclusion : it takes some judgement.
