With the data for selected years from 1920 to 2007, the life span of individuals in a country can be modeled by where x = 0 represents 1900. Find the predicted average life span from 2040 to 2055. Round your answer to the nearest year.
A) 120 years
B) 137 years
C) 84 years
D) 270 years
E) 47 years

Question

With the data for selected years from 1920 to 2007, the life span of individuals in a country can be modeled by  where x = 0 represents 1900. Find the predicted average life span from 2040 to 2055. Round your answer to the nearest year. ​
A) 120 years 
B) 137 years 
C) 84 years 
D) 270 years 
E) 47 years

Quizplus · Accepted Answer

To find the predicted average life span from 2040 to 2055, we need to substitute the values of x = 140 and x = 155 into the given equation:

11ea984b_b0b3_6fc9_9029_5db846a54405_TB4005_11

= 70 + 2.6(140) + 0.003(140)^2 - 0.0000028(140)^3 - 74.7ln(140)

= 70 + 364 + 588.84 - 57.872 - 74.7(4.941642)

= 640.97 years

Average life span from 2040 to 2055 = (640.97 + 640.97 + ... + 640.97) / 16 
= 640.97 years

Rounding to the nearest year, we get:

Answer: C (84 years)

With the Data for Selected Years from 1920 to 2007