The graph below represents the pressure and volume for a gas undergoing a cyclic process. Assume that $Y$ and $Z$ are on the same horizontal line, and $Z$ and $X$ are on the same vertical line. The part of the cyclic process from $X$ to $Y $is an isothermal process.

If the pressure of the gas at $X$ is $4.0\ kPa$, and the volume is 6.0 cubic meters, and if the pressure at $Y$ is $8.0\ kPa$, what is the volume of the gas at $Y$? *(The graph is not necessarily drawn to scale).*