Answer
The pressure decreases by less than 50%.
Work Step by Step
We know that:
$ \frac{P_1}{P_2}= \frac{V_2}{V_1}^ \gamma$
$ \frac{V_2}{V_1}= \frac{P_1}{P_2}6 \gamma$
Plugging in the known values gives the ratio as:
.7485
Thus, the pressure decreases by less than 50%.