i want to calculate the frequency

Define frequency.

This formula will return the count of 1's in the range A2, A26, A50, A74:

=SUMPRODUCT(--(MOD(ROW(A2:A74),24)=2),--(A2:A74=1))

Or, this version will account for new row insertions above the range:

=SUMPRODUCT(--(MOD(ROW(A2:A74)-ROW(A2),24)=0),--(A2:A74=1))


--
Biff
Microsoft Excel MVP


"Reza" wrote in message
...
i want to calculate the frequency of a set of numbers in a column that are
spaced 24 rows apart, i.e. want to calculate the frequency for the
following
values, A2,A26,A50,A74...etc..