SOLUTION: Wow I don't understand this it says in 1990, the life expectancy of males was 64.7 years. In 1995 it was 67.8 years, let E represent the life expectancy in year t and let t represe
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-> SOLUTION: Wow I don't understand this it says in 1990, the life expectancy of males was 64.7 years. In 1995 it was 67.8 years, let E represent the life expectancy in year t and let t represe
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Question 249990: Wow I don't understand this it says in 1990, the life expectancy of males was 64.7 years. In 1995 it was 67.8 years, let E represent the life expectancy in year t and let t represent the number of years since 1990.
E(t)=?t+? and round to nearest tenth
Use the function to predict life expectancy in 2005
E(15)=? round to the nearest tenth
Thanks for any and all help Answer by Theo(13342) (Show Source):
m = slope of your line (I'm presuming they are asking for a straight line projection.
b = the y-intercept which is the value of E(t) when t = 0
In 1990, t = 0 because 1990 is your base year.
In 1995, t = 5 because 1995 minus 1990 = 5
In 2005, t = 15 because 2005 minus 1990 = 15
You have 2 data points to work with.
They are:
E(0) = 64.7
E(5) = 67.8
E(0) means the value of E(t) when t = 0.
E(5) means the value of E(t) when t = 5.
you can use these points to find the slope of your line.
slope of your line is equal to ((E(5) - E(0))/(5-0).
This becomes:
slope of your line is equal to ((67.8) - (64.7)) / 5 = 3.1/5 = .62
replace m with .62 and your equation becomes:
E(t) = .62 * t + b
Take either of your data points and substitute in this equation to solve for b.
Use E(t) = 64.7 when t = 0
64.7 = .62 * 0 + b which becomes 64.7 which equals b in your equation.
your equation becomes:
E(t) = .62 * t + 64.7
In 2005, t will equal 15.
Substitute for t in the equation to get:
E(15) = .62 * 15 + 64.7
Solve for E(15) to get:
E(15) = 74
To graph this equation, replace E(t) with y and replace t with x to get:
y = .62 * x + 64.7
There's a horizontal line at y = 74 to show you that the graph of the equation intersect this line when x = 15. x = 15 in the graph is the same as t = 15 in the original equation.
