R help - Aug 2011 - Using R for grouped data based calculations ???

Hi,

Has Anyone used R for descriptive statistics of Grouped Data. I have
an example below

Can someone calculate the Median of the following data using R

Miles Driven ? ? ? ? ? ? Number of Residents
0-2999 ? ? ? ? ? ? ? ? ? ? ? ? ? 10
3000-5999 ? ? ? ? ? ? ? ? ? ? 28
6000-8999 ? ? ? ? ? ? ? ? ? ? 46
9000-11,999 ? ? ? ? ? ? ? ? ?32
12,000-14999 ? ? ? ? ? ? ? ?24
15000-19,999 ? ? ? ? ? ? ? ? 11
20000 and over ? ? ? ? ? ? ?? 7

what is the median number of miles driven per resident for this sample using R

I can do this manually but I need to figure out this can be done using
R. I am not looking for an exact solution to this but to some pointers
or a nice example

thanks
-amit

On Aug 23, 2011, at 12:34 AM, Amit Jain wrote:
> Hi,
>
> Has Anyone used R for descriptive statistics of Grouped Data. I have
> an example below
>
It seems to be a big night for homework on Rhelp.
> Can someone calculate the Median of the following data using R
>
> Miles Driven             Number of Residents
> 0-2999                        10
> 3000-5999                     28
> 6000-8999                     46
----------
subtotal                       74

> 9000-11,999                  32
> 12,000-14999                 24
> 15000-19,999                 11
> 20000 and over                7
subtotal                       74
>
> what is the median number of miles driven per resident for this  
> sample using R
>
> I can do this manually but I need to figure out this can be done using
> R. I am not looking for an exact solution to this but to some pointers
> or a nice example
Look for wtd.quantile() but since the values are categorical you have  
some further implementation details to address.

-- 
David Winsemius, MD
Heritage Laboratories
West Hartford, CT