these are all info i have.
x 3 5 8 6 9
y 1 5.5 6 7 2.5
A polynomial made this text
So find it out and solve for x
can somebody help me please
Sort the data points into scending order for x.
Put the values for the first third and fifth data points into this which will give you a set of three simultaneous equations for this, which you can solve for a,b and c.
Alternativly look up quadratic regression on Google.
If you don't want a quadratic fit you can repeat the first method for a cubic or quartic.
It would also help if you provided more background information on the source of this question.