Excel weeknum conditional average

Question

Date Number Weeknum

4-Jan-96 0.094288 2

5-Jan-96 0.092872 2

8-Jan-96 0.090431 2

9-Jan-96 0.153586 2

10-Jan-96 0.029758 3

11-Jan-96 0.052083 3

12-Jan-96 0.042797 3

15-Jan-96 0.047949 3

16-Jan-96 0.053029 3

17-Jan-96 0.051588 4

18-Jan-96 0.036755 4

19-Jan-96 0.043954 4

22-Jan-96 0.067316 4

I want the average number where weeknum is a certain value -edit(and year is a certain value) without averaging for every week by hand. Does anyone know whether there is an averageif/if/other condition that can do this? Weeknum doesn't always contain 5 consecutive values because holidays are preventing that.

Answer 1

Try this:

  =AVERAGEIF(C1:C13;2;B1:B13)

Column C is the week number column.
Argument #2 is the week number you're interested in.
Column B is the column with the values to average.

Answer 2

Column A: date
Column B: value for the date
Column C: Weeknum for the date
Column E: Weeknumbers (1..52)
Column F: =SUMIF(C1:C10;E1;B1:B10)/COUNTIF(C1:C10;E1)