Problema Solution
Life Expectancy The number of years a person born
in the United States is expected to live can be approximated
by the equation y = 0.189x + 70.8, where x
is the number of years since 1970. Solve this equation
for x. Use this new equation to determine in which
year the approximate life expectancy will be 80.2 years
Answer provided by our tutors
y = 0.189x + 70.8
y - 70.8 = 0.189x
(y - 70.8)/0.189 = x
When y = 80.2,
x = (80.2 - 70.8)/0.182
= 49.7
The year, then, would be 1970 +49.7 = 2019.7