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# Excel Incorrect Array Formula usage explanation

Questions:

This is my data

``````Region    Value
East       9800
East       5592
East       6966
West       5418
``````

When I do

``````=AVERAGE(IF(A2:A5="East",B2:B5)) CTRL+SHIFT+ENTER
``````

I get

``````7452.667
``````

Which is the right answer. But when I do

``````    =AVERAGE(IF(A2:A5="East",B2:B5))  ENTER
``````

I don’t get an error. I get

``````6944
``````

If I just typed

`````` =IF(A2:A5="East",B2:B5)   ENTER
``````

I get

`````` 9800
``````

So 6944 is not the average of 9800. What is Excel doing here?

When I do

``````=IF(A2:A5="West",B2:B5)  ENTER
``````

I get

`````` FALSE
``````

So it looked like IF is reading the first row.. but then something weird happens to Average(If())

I have one/two question(s) and one prayer:

Questions: What is excel doing to arrive at 6944? Why did I not get an error when I did ENTER instead of CTRL+SHIFT+ENTER and is there any way to remind excel to tell me to do the right thing when dealing with Arrays?

Prayer: I can only hope that I have not produced a lot of garbage in the last few weeks when I have neglected to to CTRL-SHIFT-ENTER and done ENTER by mistake and not gotten errors and ran with what I got.

`6944` is the average of all the values. You’ll get it using `=SUM(B2:B5)/4` as well.

When you don’t use CSE, `IF` will evaluate as follows:

``````=IF(A2="East",B2:B5)
``````

When you have an array in a non-array formula in excel, you will get only one term (or element) of the array. If, for example you put the above formula (with no `AVERAGE`), `IF` evaluates the cell corresponding to the row the formula was inserted in. The actual ‘result’ formula would be the following if you put it in the 2nd row of excel (in any of the cells C2, D2, E2, etc):

``````=IF(A2="East", B2)
``````

What will happen if you put it in cell C3 is:

``````=IF(A3="East", B3)
``````

And if you put it in C6… `A2:A5` will return `#VALUE!`, since the corresponding row of 6 in `A2:A5` doesn’t exist!. In C5, of course, you’d get `=IF(A5="East", B5)` which would return `FALSE` with your sample values.

Following from the initial formula, since `A2` is indeed `East`, you’ll get the result as `AVERAGE(B2:B5)`.

Same with the other function:

``````=IF(A2="West",B2:B5)
``````

Returns `FALSE`, and average of `FALSE` is `0`.

You might use the function `AVERAGEIF` which doesn’t need to be array entered to work, but that’s assuming that you have Excel 2007 or later versions:

``````=AVERAGEIF(A2:A5,"East",B2:B5)
``````

If you don’t want to use an array function and is stuck with an excel version before 2007, for example, Excel 2003, you can try:

``````=SUMIF(A2:A5,"East",B2:B5)/COUNTIF(A2:A5,"East")
``````