Find an approximating polynomial of known degree for a given data.

Example:
For input data:

x = {0,  1,  2,  3,  4,  5,  6,   7,   8,   9,   10};
y = {1,  6,  17, 34, 57, 86, 121, 162, 209, 262, 321};

The approximating polynomial is:

3 x2 + 2 x + 1

Here, the polynomial's coefficients are (3, 2, 1).

This task is intended as a subtask for Measure relative performance of sorting algorithms implementations.

# The polynomial approximation
f(x) = a*x**2 + b*x + c
 
# Initial values for parameters
a = 0.1
b = 0.1
c = 0.1
 
# Fit f to the following data by modifying the variables a, b, c
fit f(x) '-' via a, b, c
   0   1
   1   6
   2  17
   3  34
   4  57
   5  86
   6 121
   7 162
   8 209
   9 262
  10 321
e
 
print sprintf("\n --- \n Polynomial fit: %.4f x^2 + %.4f x + %.4f\n", a, b, c)