Median on Ref data Line

[#1]

I have created a chart with below sample values for 4 months.

Date, Count of Sales

1-Jan-12,10

2-Jan-12,11

.

15-Feb-12,50

.

30-Mar-12,35

.

30-Apr-12,1000

Later I created a graph to calculate monthly total of sales using dimension as = Month(Date) &"-" & Year(Date).

Now If I have to add median/avg line of Monthly sale on this chart how to get it added?

When I created simple graph of date Vs Count, I was able to add Two refernce lines using Avg(Count of Sales) and Median(Count of Sales) functions for reference line of graph.

But when I create monthly aggregation of data, I don't know how to add correct "avg/median function" for this table.

Any help will be appreciated.

[#2]

Ok Avg is solved. I found the answer already. Really sorry to put this question on QV forum.

[#3]

can teach me hw to add a median line on my scatter graph?

i would like to add a median like which is accross all the points.