how to create Avg and Stdev for Fractile expression

[#1]

Hi,

In my app, i'm using Dimension as "MonthYear" and Expression as "=Fractile({$<Year=,Month=,Day=>}BC_PPK,0.1)" in Line Chart object.

Now i want to create 2 more expression, Average and StandardDeviation for first expression i.e(above expression)

How can i write an expression of Avg and Stdev for the expression "=Fractile({$<Year=,Month=,Day=>}BC_PPK,0.1)"

Please can anyone suggest on this.

Regards,

Satish