Answer:
If this trend continues, life expectancy will be 73 years in the year 1990
Step-by-step explanation:
Hi
first of all, we build a model with the knowns of the problem, so we have [tex]LifeExpectancy=LE(x)=55+0.2x, x[/tex] in years after 1900, then we have
[tex]73=55+0.2x[/tex] as we isolate for [tex]x[/tex], [tex]x=\frac{73-55}{0.2}=90[/tex], finally, we obtain that the birth year which the average life expectancy will be 73 years is 1990