demographic research shows that for a certain group of 22000 births, the number of individuals, L, who live to age x years is modelled by the function L(x)= -0.0035x^(4)+0.0045x^(3)+0.85x^(2)-35x =22000, 0<=x<=95. Determine (dL)/(dx) x=10. Interpret the e=meaning of this vakue for this situation