Population Growth In \(2000\) India's population reached \(1\) billion, and it is projected to be \(1.4\) billion in \(2025\) . (Data from U.S. Census Bureau.)
(a) Find values for \(P _ { 0 }\) and \(a\) so that \(P ( x ) = P _ { 0 } a ^ { x - 2000 }\) models the population of India in year \(x\) . Round \(a\) to five decimal places.
(b) Predict India's population in \(2020\) to the nearest tenth of a billion.
(c) In what year is India's population expected to reach \(1.5\) billion?