Dear all,
My questions is simple but it seems i can not see the solution:
I have 3 columns in an excel sheet
1 is with percentage complete of an activity
2 is with weight (ManHours assigned / Total ManHours)
3 is the activity name
Now i need to put all activities under a certain name, summed in 1
cell
example:

Description1 actual % complete weight/desc

Under Ground Concrete Work 100% 1.3%
Under Ground Concrete Work 100% 5.1%
Under Ground Concrete Work 100% 0.7%
Under Ground Concrete Work 100% 5.0%
Under Ground Concrete Work 100% 4.6%
Above Ground Concrete Work 100% 49.4%
Above Ground Concrete Work 100% 50.6%

Now i need to summup under a cell called underground concrete, column
called AREA1, all under ground concrete by the result of each (actual
% complete * weight/desc) like (100% * 1.3%) + (100% 5.1% ) + (100%
0.7%) etcetera ...
what i found that it should be done by sumproduct but how, i cant
figure out could you please inform me?