SOLUTION: The population of a particular country was 28 million in 1985.In 1994,it was 32 million. The exponential growth function A=28e^kt describes the population of this country t years a

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: The population of a particular country was 28 million in 1985.In 1994,it was 32 million. The exponential growth function A=28e^kt describes the population of this country t years a      Log On


   



Question 1129512: The population of a particular country was 28 million in 1985.In 1994,it was 32 million. The exponential growth function A=28e^kt describes the population of this country t years after 1985.Use the fact that 9years after 1985 the population increased by 4 million to find k. Round answer three decimal places.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+A+=+28%2Ae%5E%28k%2At%29+
+32+=+28%2Ae%5E%28k%2A9%29+
+e%5E%28k%2A9%29+=+1.14286+
Take the natural log of both sides
+9k+=+.133531+
+k+=+.014837+
+A+=+28%2Ae%5E%28+.015t+%29+
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check answer:
+32+=+28%2Ae%5E%28+.015%2A9+%29+
+32+=+28%2Ae%5E.135+
+32+=+28%2A1.1445+
+32+=+32.046+
error due to rounding off -check math