explain hoe to calculate it from the figure: Nitrocellulose fibers with an initial total water content of $40wt\%($dry basis$)$ are dried in

trays in a tunnel dryer operating at $1$atm. If the fibers are brought to equilibrium with air

at $25C$ and a relative humidity of $30\%,$ determine the $kg$ of moisture evaporated per $kg$ of

bone$-$dry fibers. The equilibrium$-$moisture content of the fiber is given in attached Figure