Answer
$P_2=21atm$
Work Step by Step
The required pressure can be determined as follows:
According to Boyle's law
$P_1V_1=P_2V_2$
This can be rearranged as
$P_2=\frac{P_1V_1}{V_2}$
As given that $V_2=\frac{1}{4}V_1$
$\implies P_2=\frac{5.3atm \times V_1}{\frac{1}{4}V_1}$
This simplifies to:
$P_2=21atm$
