Calculating Standard Deviation with If in Excel

Question

I have a dataset with two columns. One label and one number. Using sumif and countif, I managed to calculate the average of each label in groups. Now, I am trying to do the same with Standard Deviation but I have a problem:

=STDEV.P(IF($A$2:$A$625129=F4,$B$2:$B$625129))

This is the formula I use, where A column is the column with the labels, B with the numbers and F4 is one of the label groups. The result is 0. I do the same for every label group and all of them are 0. Any idea what is wrong in the formula?

Edit: After the comment, I tried to apply the formula as an array one and it almost worked. Now, the only problem is that the cell F4 is static whereas I want it to be dynamic (F5, F6, F7 etc) for every cell in array formula.

Answer 1

For the sake of an answer (courtesy @barry houdini):

You need to put the formula in a single cell first, then apply CTRL+SHIFT+ENTER....and then copy down