The population, P, in millions, of Ethiopia was 72.5 million in 2004 and growing at an annual rate of 2.5%. Let t be time in years since 2004. (a) Express P as a function in the form P=P0 a^t. P= (b) Express P as an exponential function using base e rounding the continuous growth rate to five decimal places. (c) Compare the annual and continuous growth rates.