predict next number

[Excel777]

hello all
if i want to predict the next number which between 1 and 2000 and i already have set of 3 numbers

500
1750
320
???

is there any way to predict the 4th number ???

thanks in advance

 

[Andrew Fergus]

If there was a rule stipulating how n is related to n+1 then the answer is yes. However, any number of relationships between the numbers can be guessed at (of which all but 1 will be incorrect) with such a small sample. I recommend having a larger sample before trying to predict the next number.

 

[StephenCrump]

If there is some pattern to the progression, yes.

If they are random numbers, no.

 

[Macropod]

With so few data points, the possibilities are numerous. For example:
=949*ROW()^3-7034*ROW()^2+15709*ROW()-9124

 

[Excel777]

With so few data points, the possibilities are numerous. For example:
=949*ROW()^3-7034*ROW()^2+15709*ROW()-9124

is this a formula i should enter or what u mean
thanks for help

 

[Macropod]

Yes, it's a formula. You could have tried it instead of asking...

If you input it on row 1 and copy down to row 4, you'll get a sequence with your existing first 3 numbers, then a 4th new number.

Another conforming formula - with a different result - is:
=820*ROW()^3-6260*ROW()^2+14290*ROW()-8350
or:
=780*ROW()^3-6020*ROW()^2+13850*ROW()-8110
or:
=705*ROW()^3-5570*ROW()^2+13025*ROW()-7660
etc. And that's just with 3rd-order polynomials.

As I said:

With so few data points, the possibilities are numerous.