Hi

I would like to be able to replicate the FILL function that you get when dragging the handle (bottomm right corner) of a group of cells. For example I have a set of numbers in a column, and would like to extrapolate these further. This can be done manually by selecting the range of cells, and then dragging the handle down. This appears to give a good linear fit to the data. I have tried to replicate this manual process with the functions LINEST and TREND, but they don't appear to give a good fit.

For example:

1) Use TREND 2) manual fill 3) Use LINEST
624665216000 624665216000 624665216000
637974487552 637974487552 637974487552
658627675136 658627675136 658627675136
659456191488 659456191488 659456191488
697966489088 697966489088 697966489088

622121161830 711355599189 16808425011


1) The new value (622121161830) is determined using the function
=TREND(R[-5]C:R[-1]C)

2) The new value (711355599189 ) is determined using the manual fill option, and gives a good value, as the numbers are increasing

3) The new value (16808425011) is determined using the function
=LINEST(R[-5]C:R[-1]C)

Option 2 using the manual fill appears to give the best linear growth, can I achieve this using a function ? Both TREND and LINEST accept multiple options, but I have tried using x and y values with no luck, and I don't need to use these for the manual fill option.

Hope somebody can help.

thanks

Steve