skewness issue

[Embee]

I'm trying to find skewness for this distribution. I know how the skewness function works but I'm not sure how to deal with this dataset I have.

Bin..........Freq
0-10........78
10-20......2589
20-30......922
30-40......11


So, all I know is how many values are in each bin (not what the values are themselves). Does that mean I have to type in an arbitrary value of the 2nd bin 2589 times in order for Excel to understand what I'm looking for? Anyone know of a shorter way? Thanks.

[zhj23]

You should use the Class Mid-point and not any arbitrary value. For instance,
15 for the class 10-20.

However, EXCEL, being a non Statistical software, is quite limited on this.
(You have to type 2589 of the 15s). It is better to use a high grade
statistical software, such as SPSS to avoid the tedious typing.

Zhj23

"Embee" wrote:

>
> I'm trying to find skewness for this distribution. I know how the
> skewness function works but I'm not sure how to deal with this dataset
> I have.
>
> Bin..........Freq
> 0-10........78
> 10-20......2589
> 20-30......922
> 30-40......11
>
>
> So, all I know is how many values are in each bin (not what the values
> are themselves). Does that mean I have to type in an arbitrary value
> of the 2nd bin 2589 times in order for Excel to understand what I'm
> looking for? Anyone know of a shorter way? Thanks.
>
>
> --
> Embee
> ------------------------------------------------------------------------
> Embee's Profile: http://www.excelforum.com/member.php...o&userid=31455
> View this thread: http://www.excelforum.com/showthread...hreadid=511415
>
>

[Jerry W. Lewis]

You can use an array formula, such as

=SKEW(ISNUMBER(ROW(A1:A78))*AVERAGE(0,10),ISNUMBER(ROW(A1:A2589))*AVERAGE(10,20),ISNUMBER(ROW(A1:A922))*AVERAGE(20,30),ISNUMBER(ROW(A1:A11))*AVERAGE(30,40))

array entered (Ctrl-Shift-Enter), which will give the result
0.692746935115446. If you get zero, then you did not array enter it.

ISNUMBER(ROW(A1:A78))*AVERAGE(0,10), produces an array of 78 numbers, each
with the value 5 (the midpoint of 0-10), ...

Jerry

"Embee" wrote:

>
> I'm trying to find skewness for this distribution. I know how the
> skewness function works but I'm not sure how to deal with this dataset
> I have.
>
> Bin..........Freq
> 0-10........78
> 10-20......2589
> 20-30......922
> 30-40......11
>
>
> So, all I know is how many values are in each bin (not what the values
> are themselves). Does that mean I have to type in an arbitrary value
> of the 2nd bin 2589 times in order for Excel to understand what I'm
> looking for? Anyone know of a shorter way? Thanks.
>
>
> --
> Embee
> ------------------------------------------------------------------------
> Embee's Profile: http://www.excelforum.com/member.php...o&userid=31455
> View this thread: http://www.excelforum.com/showthread...hreadid=511415
>
>