The Population of a Certain Region Was 10 Million in 1950

Short Answer

The population of a certain region was 10 million in 1950. By 1970, it had increased to 13.5 million. Assuming exponential growth, estimate the population in the year 2000.
Enter your answer exactly in the form a $\mathrm { e } ^ { \mathrm { C } }$ (no units).