Finding the Median with Class Scores

[danago]

If I am given a frequency table, but instead of set scores, i am given classes, or a range of scores. So for example:

20-29 | 11
30-39 | 12
40-49 | 2

etc.

If asked to find the median of the set of data, should i give the midpoint of the class containing the median score, or should i give the whole class. So in the example above, should i give 34.5, or 30-39?

Thanks in advance,
Dan.

 

[Dick]

Think of some example sets of scores that fit your grouping. Do they all have median 34.5?

 

[danago]

No they dont, so id give the class boundaries then?

Thanks,
Dan.

 

[Dick]

No they dont, so id give the class boundaries then?

Thanks,
Dan.

I can't think what else you would do. BTW the class boundaries would suggest that all of the scores are integers.

 

[danago]

I can't think what else you would do. BTW the class boundaries would suggest that all of the scores are integers.

How is that so? Why does it suggest all scores are integers?

 

[Dick]

How is that so? Why does it suggest all scores are integers?

Because e.g. 39.5 is not in any range.

 

[danago]

Oh i see. If i changed it to:

20 <= x < 29 | 11
29 <= x < 39 | 12
40 <= x < 49 | 2

Then that would allow for all scores within the boundaries, integers or not?

 

[Dick]

Yep. Right.

 

[danago]

ok, thanks