On Sat, 27 Aug 2005 09:04:01 -0700, "DBane"
wrote:

Thank you for your reply.
I am lost as to what values need to be placed in the known y's,known x's,
I presume the new x's are the range. what is the const. The length does vary
each week, The range of the figures will be between 20 and 120.
They will change daily. Never more than 8,nor less than 4 figures in the
range. thank you for your patience. My limited knowledge of excel comes from
dummies 101:Excell 97.

"Ron Rosenfeld" wrote:

On Fri, 26 Aug 2005 15:28:02 -0700, "DBane"
wrote:

I have a column of figures 20,30,40,50,60. when I select the range and put
the + at the bottom and pull, the result shows 70. the same using chart
wizard, line, right clicking add treadline. Linear, option, forcast 1
forward,the result 70 also. What formula do I have to place in the cell range
to get the return 70. I have tried trend and forcast. Totally lost.


=TREND(B3:B7,,6)

Or, if the length of your list will vary each week:


--ron


Did you try the formula I posted?

If you did, and looked at HELP, you would see that B3:B7 are in the slot for
"known y's"; that the slot for "known x's" is blank; and that the slot for
Constant (an optional argument) is not used.

B3:B7 is the location of your column of figures 20,30,40, etc.

Since these represent x=1 to x=5; and since you are interested in what is 'y'
when x=6, the 6, is in the 'new x' slot.

I will leave it to you to figure out what Excel is doing with regard to the
"known x's". If you cannot figure that out, post back as otherwise you will
not be able to understand what is going on.

Since the length of the list will vary, try this formula instead -- it is the
equivalent except it can deal with a list of varying length. The formula
assumes that your first entry is in B3, that the entries are in sequential
cells down to no further than B20, and that the cells after your entries are
blank; so alter that if the assumptions I've posted are incorrect:

=TREND(OFFSET(B3,0,0,COUNT(B3:B20)),,COUNT(B3:B20) +1)


--ron