I need help on the following:

Find the matrix of the linear transformation $\displaystyle T(f(t)) = \int_{-6}^{7} f(t) dt $ from $\displaystyle P_3 $ to $\displaystyle \mathbb {R} $ with respect to the standard bases for $\displaystyle P_3 $ and $\displaystyle \mathbb {R} $.

Thanks