I tried to create equations from the set of data by solver
x= 90021 85248 78314 69768 59508 47975
y = 20.09 19.92 18.70 16.95 16.13 15.67

in the form of y= a + bx +cx2 + dx3;
where x2= x square ,x3 = x cube.

but could not do so.
the solver does fine when the value of x is small .
Your help will be hghly appreciated in this regard.

Thanks