The following schematic diagram shows a chemostat with cell recycle
where $\mathrm{F}_0$ and $\mathrm{F}_{\mathrm{r}}$ are the volumetric flow rates (in $L \cdot h^{-1}$ ) of feed and recycle streams, respectively. $\mathrm{X}_1, \mathrm{X}_0$ and $\mathrm{X}$ are the cell concentrations (in $g \cdot L^{-1}$ ) in the reactor, recycle-stream and product-stream, respectively. If $\frac{X_0}{X_1}=1.5, \frac{F_r}{F_0}=0.7$ and $\mathrm{X}_1$ is $7.3 \mathrm{~g} \cdot L^{-1}$, the value of $\mathrm{X}$ (in $g \cdot L^{-1}$, rounded off to one decimal place) is ________________.
