Answer
0.65 V
Work Step by Step
We are told the gain of the transistor amplifier and the ac base current, so we can calculate the ac output current.
$$i_C=(\beta)( i_B)$$
Use Ohm’s law. The ac output current (collector) multiplied by the output resistance equals the ac output voltage.
$$V_{out}=i_CR_C=(\beta)( i_B)(R_C)$$
$$ = (85)(2.0\times10^{-6}A)(3.8\times10^3 \Omega)=0.65 V$$
