Here is what I have so far to gather the records that need to be aggregated. How do I determine the lenght weighed average of the MBit column?

select a.*,b.seq prec,c.seq nrec from wells a

join wells b on a.evalnum = b.evalnum and a.holeid=b.holeid and a.seq = b.seq -1 and b.oreflag = 'y'

join wells c on a.evalnum = c.evalnum and a.holeid=c.holeid and a.seq = c.seq +1 and c.oreflag = 'y'

where a.oreflag = 'n' and a.length < 1and a.length < b.length and a.length < c.length

union

select d.*,0,0 from wells d

join

(select a.*,b.seq prec,c.seq nrec from wells a

join wells b on a.evalnum = b.evalnum and a.holeid=b.holeid and a.seq = b.seq -1 and b.oreflag = 'y'

join wells c on a.evalnum = c.evalnum and a.holeid=c.holeid and a.seq = c.seq +1 and c.oreflag = 'y'

where a.oreflag = 'n' and a.length < 1and a.length < b.length and a.length < c.length

) set1 on d.seq=set1.prec

union

select d.*,0,0 from wells d

join

(select a.*,b.seq prec,c.seq nrec from wells a

join wells b on a.evalnum = b.evalnum and a.holeid=b.holeid and a.seq = b.seq -1 and b.oreflag = 'y'

join wells c on a.evalnum = c.evalnum and a.holeid=c.holeid and a.seq = c.seq +1 and c.oreflag = 'y'

where a.oreflag = 'n' and a.length < 1and a.length < b.length and a.length < c.length

) set1 on d.seq=set1.nrec