# Mean Grouped Data

• Mar 29th 2010, 04:56 PM
vsky
Mean Grouped Data
Heu guys,

Just need some quick help on finding the mean of group data.

I know the formula and how to get the answer, i.e. fx, but how do you go about it when the question is to do with ages, such as, 50 and over and also less than 33? How would you estimate a number to times by the frequency.

Like:

Ages...

< 33
34
35
36-40
41-47
48
49
50 >

For the exact numbers, times by the frequency. For the 36-40 the midpoint then times by frequency... but what about the < and > parts since its ages?

Any help would be really appreciated, cheers.
• Mar 29th 2010, 05:16 PM
pickslides
Quote:

Originally Posted by vsky
For the exact numbers, times by the frequency. For the 36-40 the midpoint then times by frequency... but what about the < and > parts since its ages?

That is a problem, a weakness in the detail of your data. There is no right answer here. You either ignore these class intevals or pick a figure for them. I suggest making the difference equal at either end.

I.e if you pick 30 for < 33, then pick 53 for >50.
• Mar 30th 2010, 10:09 AM
vsky
ok thank youu!