https://communities.sas.com/t5/SAS-Enterprise-Guide/HELP-how-to-calculate-stand-density-for-forestry-survey/m-p/10469#M2614 Hi, I carried out stratified sampling of a forest area, and I'm able to work out what the average stem density is per hectare with all associated summary stats, (sd, etc) but then i need to work out what the total stem density is on the total parcel of land (that means multiplying the stem density by the total number of hectares, right? But I don't know how to do this in SAS EG4 so that i can get the sd of the total figure....help, tearing my hair out at the roots! Mon, 02 Nov 2009 08:44:00 GMT deleted_user 2009-11-02T08:44:00Z https://communities.sas.com/t5/SAS-Enterprise-Guide/HELP-how-to-calculate-stand-density-for-forestry-survey/m-p/10469#M2614 Hi, I carried out stratified sampling of a forest area, and I'm able to work out what the average stem density is per hectare with all associated summary stats, (sd, etc) but then i need to work out what the total stem density is on the total parcel of land (that means multiplying the stem density by the total number of hectares, right? But I don't know how to do this in SAS EG4 so that i can get the sd of the total figure....help, tearing my hair out at the roots! Mon, 02 Nov 2009 08:44:00 GMT https://communities.sas.com/t5/SAS-Enterprise-Guide/HELP-how-to-calculate-stand-density-for-forestry-survey/m-p/10469#M2614 deleted_user 2009-11-02T08:44:00Z https://communities.sas.com/t5/SAS-Enterprise-Guide/HELP-how-to-calculate-stand-density-for-forestry-survey/m-p/10470#M2615 I'm not a stat person, so I'm going to punt on this...<BR /> <BR /> Try SAS Tech Support (it's free to all SAS customers!) at: <A href="http://support.sas.com/techsup/contact/" target="_blank">http://support.sas.com/techsup/contact/</A>. I'm not sure whether you should have them route you to a Stat expert or an EG expert -- I would probably tell them you have a stat question since that's the tougher part here.<BR /> <BR /> Perhaps someone else on this forum can provide advice, which would be excellent. I know enough about sampling to say with confidence that I don't know how to calculate standard deviation on the whole population based on just a sample. <span class="lia-unicode-emoji" title=":slightly_smiling_face:">🙂</span> Mon, 02 Nov 2009 16:21:19 GMT https://communities.sas.com/t5/SAS-Enterprise-Guide/HELP-how-to-calculate-stand-density-for-forestry-survey/m-p/10470#M2615 RichardH_sas 2009-11-02T16:21:19Z