> And that would be the integral from 9.5 to 10.5 of the density function.
>> you cannot replace the integral of a function with the function itself
.zo'o: He is computing the integral over an interval of width 1, approximating the function with a polynomial of grade 0.
A polynomial of degree zero is not necessarily a good approximation though. If you are to approximate 1+x^10 with a constant polynomial (of degree 0), you'd likely choose the approximation f(x)=1. That'll give you a huge error at x=2 though ...