For x = 0.9000000000, approximating P(x)

0.6000000000 , -0.1769446000
0.7000000000 , 0.0137522700
0.8000000000 , 0.2236336200
1.0000000000 , 0.6580919700

-0.1769446000 0.0137522700 0.2236336200 0.6580919700 
1.9069687000 2.0988135000 2.1722917500 
0.9592240000 0.2449275000 
-1.7857412500

For x = 0.9000000000, P(x) = 0.4419850025