Since 1960, the growth in world population (in millions) closely fits the exponential function defined by A(t) = 3184e^0.0158t, where t is the number of years since 1960.

(a) World population was about 3701 million in 1970. How closely does the function approximate this value?
(b) Use the function to approximate world population in 2015. (The actual 2015 population was about 7383 million.)
(c) Estimate world population in the year 2025.