help someone please:

Question

In 1993 the life expectancy of males in a certain country was 71.2 years. In 1997 it was 73.4 years. Le E represent the life expectancy in year t represent the number of years since 1993

E(t)= ___t + ___ ?

use the function to predict the life expectancy of males in 2009
E(16)=?

Answer 1

Basically, you count the number of years from 1933 to 1997 which is 64 years and see how much the life expectancy has increased. That will be 73.4 - 71.2 = 2.2 years. How much is that per year. That will be 2.2/64 = 0.03438. So the E(t) from 1933 would be 0.03438(t) + 64. Your question doesn't ask for the year since 1933 but for the year since 1993. Can't you calculate the amount that should be subtracted from 1997 (or added to the year 1933) so you start from 1993 instead of 1997.