Answer
a. 130.
b. 8700.
Work Step by Step
a. See page 851. Using the second equation on that page, which is not numbered, we calculate the voltage gain as the collector ac voltage, divided by the base ac voltage.
$$\beta_V=\frac{V_C}{V_B}=\frac{i_CR_C}{i_BR_B}=\beta_i\frac{R_C}{R_B}$$
$$=65\left(\frac{7.8k\Omega}{3.8k\Omega}\right)\approx130$$
b. Calculate the power amplification as the output power, divided by the input power.
$$\beta_P=\frac{i_CV_C}{i_BV_B}=\beta_i\beta_V=(65)(133.4)\approx 8700$$