A mathematical model for population growth over short intervals is given by P = Poe"l, where Po is the population at time t= 0, r is the continuous compound rate of growth, t is the time in years, and P is the population at time t. Some underdeveloped nations have population doubling times of 56 years. At what continuous compound rate is the population growing? . . . Substitute the given values into the equation for the population. Express the population at time t as a function of Po. Po = Poe (Simplify your answers.) For the population to double in 56 years, the continuous compound growth rate is %. (Type an integer or decimal rounded to two decimal places as needed.)