Averaging duplicate entries with standard deviation

I have a 3423x3 dimension dataset (lon x lat x soil microbial biomass)

There are several datapoints that have the same lat x lon I want to average these duplicated datapoints into just one bin AND also calculate the standard deviation associated with each average

EX:

[25 20 10; 25 20 20; 25 21 5; 13 21 10]

I want to be..

[25 20 15; 25 21 5; 13 21 10]

Is there any way to do this on matlab? Thank you for any help

-Melissa

[Geoff Hayes]

Melissa - are your latitude and longitude values simply integers or can they include a fraction (i.e. 25.2, 20.34, etc.)?