Assumptions:

A2:E5 contains your data

By 'best average price' you mean lowest average price

Formula:

=INDEX(A2:A5,MATCH(MIN(SUBTOTAL(1,OFFSET(B2:E5,ROW (B2:E5)-ROW(B2),0,1))),
SUBTOTAL(1,OFFSET(B2:E5,ROW(B2:E5)-ROW(B2),0,1)),0))

....confirmed with CONTROL+SHIFT+ENTER, not just ENTER. If by 'best' you
mean highest average price, change MIN to MAX.

Hope this helps!

In article ,
TUNGANA KURMA RAJU wrote:

I am looking for a function that gives me best average rate from a table
without creating a helper column. col A is date ,col B to col E price1 ,price
2,price 3,price 4.
dates in col A are in ascending order but not continuous.By looking from
certain date in col a ,on whice date the best average price arrived.
date price 1 price 2 price 3 price 4
02-jan 114.5 116.7 112.85 115 (avg.price=114.76)
compare this avg rates all rows till end of the table