Standard Deviation limited by multiple criteria

[JeffFinnan]

I already had assistance get standard deviations for multiple columns here:

https://www.mrexcel.com/board/threads/combined-standard-deviation-of-two-separate-columns-of-data.1244401/

Now, I would like to limit the data included based on a date from another column. This formula works fine:

 =STDEV(IF(A6:A2000="Cc",IF(ISNUMBER(D6:D2000),D6:D2000)),IF(K6:K2000="Cc",IF(ISNUMBER(I6:I2000),I6:I2000)))

Columns A and K contain text and blank cells. Columns D and I contain numbers and cells with #N/A if there is no number available in those particular cells. I use the #N/A for plotting purposes. Now I would like to limit the data further based on date. In this data set Column C contains dates and #N/A related to the numbers in Column D. I have a particular date in U45. If I use this array formula:

=STDEV(IF(AND(A6:A2000="Cc",C6:C2000>U45),IF(ISNUMBER(D6:D2000),D6:D2000)),IF(K6:K2000="Cc",IF(ISNUMBER(I6:I2000),I6:I2000)))

I get a #N/A. I presume that the problem is the presence of #N/A in Column C. I am not sure how to work an ISNUMBER for Column C.
How can I achieve limiting the data set based on date too? I will also eventually include the same date limitation to the data in Column I using a date Column H.

 

[Domenic]

Try it like this...

=STDEV(IF(A6:A2000="Cc",IF(ISNUMBER(C6:C2000),IF(C6:C2000>U45,IF(ISNUMBER(D6:D2000),D6:D2000)))),IF(K6:K2000="Cc",IF(ISNUMBER(H6:H2000),IF(H6:H2000>U45,IF(ISNUMBER(I6:I2000),I6:I2000)))))

Hope this helps!

 

[JeffFinnan]

Thanks much. Works perfectly. And have replaced STDEV with AVERAGE and Count to get those numbers too.