SOLUTION: The average life expectancy for American men born in 1900 was 55 years. Life expectancy has increased by about 0.2 year for each birth year after 1900. If this trend continues, f
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Question 188144: The average life expectancy for American men born in 1900 was 55 years. Life expectancy has increased by about 0.2 year for each birth year after 1900. If this trend continues, for which birth year will the average life expentancy be 91 years?
I think the answer is 2080. I just have no idea how to put this in algebraic terms. Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! The average life expectancy for American men born in 1900 was 55 years.
Life expectancy has increased by about 0.2 year for each birth year after
1900.
If this trend continues, for which birth year will the average life expectancy be 91 years?
:
Using the form: y = mx + b
From the given information we can say the slope (m) of the equation will be +.2
(slope is rise/run; it goes up .2 for each year)
:
the y intercept (b) will be 55, so we have
y = .2x + 55
Where
y = life expectancy x years after 1900
:
"If this trend continues, for which birth year will the average life expectancy be 91 years?"
replace y with 91, solve for x
.2x + 55 = 91
.2x = 91 - 55
.2x = 36
x =
x = 180 yrs after 1900 which is 2080, so you thought correctly.
