The U.S. population is approximated by the function where P(t) is measured in millions of people and t is measured in 30-year intervals, with t = 0 corresponding to 1930. What is the expected population of the United States in 2020 ( t = 3 )?
A) 408.0 millions
B) 322.6 millions
C) 616.3 millions
D) 325.6 millions

Question

The U.S. population is approximated by the function  where P(t) is measured in millions of people and t is measured in 30-year intervals, with t = 0 corresponding to 1930. What is the expected population of the United States in 2020 ( t = 3 )? ​
A) 408.0 millions 
B) 322.6 millions 
C) 616.3 millions 
D) 325.6 millions

Quizplus · Accepted Answer

We plug in t = 3 for 2020 (since 2020-1930 = 90 which is exactly 3 30-year intervals from 1930):
P(3) = 11e^(0.018(3)) = 11e^(0.054) ≈ 322.6 millions (rounded to one decimal place)

The US Population Is Approximated by the Function Where P(t)