I have a pivot field

Amount Cases
Branch
a 100 2
b 200 5
c 300 3
d 200 2

Now, I have inserted a calculated field by InsertCalculated Field showing
Amount per case ("Avg"), Amount/Cases as follows:

Amount Cases Avg
Branch
a 100 2 50
b 200 5 40
c 300 3 100
d 200 2 100

Now, when I group this data as branch a & b as Zone 1 and c & d as Zone 2 as
the group toals are showing the sums of Amount & Cases but not calculating
the "Avg" field as follows:

Amount Cases Avg
Zone Branch
Zone-I a 100 2 50
b 200 5 40
Zone-I Sum 300 7 ?

Zone-II c 300 3 100
d 200 2 100
Zone-II Sum 500 5 ?

Brand Total 800 12 ?