Excel is doing its job correctly.

It counts equal to or less than each bin number.

Change your bin numbers to 19, 29, 39, 49

You will get 0, 3, 2, 1, 0

Do not forget to add one more cell to the bins array when entering the
formula.

{=FREQUENCY(A1:A6,B1:B4)} array entered in D1:D5


Gord Dibben MS Excel MVP

On Fri, 22 Jan 2010 13:38:02 -0800, Jake
wrote:

The histogram analysis is automatically grouping fish lengths into the next
larger bin-class (For example: 20 is considered part of the 20-bin; 21 and
24 are included in the 30 bin). From what I understand it is supposed to
group into the bin of equal or greater size, up to the next bin-class.

Ex. Fish Lengths (20 cm, 21, 24, 30, 32, 40)

Bin is (20, 30, 40, 50)

What it is doing: Frequencies (20 is 1; 30 is 3; 40 is 2, and 50 is 0)
What it should be doing: Freqs (20 is 3; 30 is 2; 40 is 1; and 50 is 0)

Please help!