Linear regression slope over variable range

[artz]

Hi,

I want to return the linear regression slope (in cell N4) of the last 5 values in a data set. The data set begins on row 8 in columns C (x values) and AA (y values). The last row with data in these columns will vary which is why I can't use the cell formula:

=SLOPE(C255:C259,AA255:AA259)

Can anyone modify this formula to work regardless of the number of rows? And although I stated that I wanted the linear regression slope for the last 5 values, it would be great I could set the number of values included the calculation based on the value in cell AA2.

Thanks,

Art

 

[shg]

Maybe...

=SLOPE(INDEX(C:C,   MATCH(9E+307, C:C  )):INDEX(C:C,   MATCH(9E+307, C:C  )-4), 
       INDEX(AA:AA, MATCH(9E+307, AA:AA)):INDEX(AA:AA, MATCH(9E+307, AA:AA)-4))

 

[artz]

shg,

Thanks so much, works perfectly.

Art