Query SOQL in a range of values ordered by another field

This will work dynamicaly for whatever the list size is but only takes top 5 and bottom 5 of the record A assuming record A is located at the center of the list. therefore, its always average of 10 numbers.

list<objecttype> recordsfetched=new list<objecttype>();
	recordsfetched=[select fieldA,FieldB from object order by FieldB desc];
	integer sumoftopfivenumbers=0;
	integer sumofbelowfivenumbers=0;
	integer avg=0;
	integer mid=0;
		if(recordsfetched.size()!=NULL&&recordfetched.size()>=10){
			//deciding on the position of Record A  based on size of list
				if(recordsfetched.size()%2==0){
					mid=recordsfetched/2;
				}
				else{
					mid=(recordsfetched+1)/2;
				}
			//calculates sum of top 5 numbers of A record
				for(integer i=mid-1;i<=mid-5 ;i--){
			sumoftopfivenumbers=(recordsfetched[i].fieldA)+sumoftopfivenumbers;
				}
		   //calculates sum of bottom 5 numbers of A record
				for(integer i=mid+1;i<=mid+5;i++)
				{
					sumofbelowfivenumbers=(recordsfetched[i].fieldA)+sumofbelowfivenumbers;
				}
				//calculates average of top 5 and below 5 of record A
			avg=(sumoftopfivenumbers+sumofbelowfivenumbers)/10;
    //places average value in fieldA which is the mid value of the list
	recordsfetched[mid].feildA=avg;
   }

Hope this helps, Mark it as solved if it did.