In 1992, the life expectancy of males in a certain country was 73.5 years. In 1996, it was 75.7 years. Let E representthe life expectancy in yeart and let t represent number of years since 1992.

Fill in the linear function E(t) that fits the data
E(t)=____t+____

uses this to prdict the life expectancy of males in 2009

E(17)=____

To find the slope would it then be 75.7-73.5/73.5
so the slope would be 33.4? or would it just be 2.2?

1 answer

no

treat you data as two ordered pairs
(0,73.5) and (4,75.7)

then slope =(75.7-73.5)/(4-0) = .55

so your equation is
E(t) = .55t + b
using (0,73.5)
73.5 = 0 + b
b = 73.5

so E(t) = .55t + 73.5

for for E(17) = .55(17) + 73.5 = 82.85