A continuous culture is operated at steady state using glucose as a limiting substrate. The conditions are So (feed glucose) = 20 g/L, S = 0.02 g/L, X =10 g/L, and D = 0.25 h−1. Now, D is changed to 0.3 h−1 and So to 15 g/L. The new D is 90% of the maximum specific growth rate. What is the cell concentration (X) at the new steady state? Assume that the growth is described by the Monod model.