v 4.6

$${\begin{align*}R &= \frac{\langle E_r H_r\rangle}{\langle E_i H_i \rangle} = \frac{E_{r0}^2}{E_{i0}^2} = \frac{I_r}{I_i} \\ T &= \frac{\langle E_t H_t \rangle}{\langle E_i H_i \rangle} = \frac{n_2}{n_1} \frac{E_{t0}^2}{E_{i0}^2} = \frac{n_2}{n_1} \frac{I_t}{I_i} \end{align*}}$$