SOLUTION: Can you please help me with this story problem that I am struggling with. In 1991 the life expectancy of males in a certain country was 63.2 years. In 1996 it was 65.7 years. Le

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Question 330783: Can you please help me with this story problem that I am struggling with.
In 1991 the life expectancy of males in a certain country was 63.2 years. In 1996 it was 65.7 years. Let E represent the life expectancy in year t, and let t represent the number of years since 1991.
The linear function E(t) that fits the data is E(t)=___t + ___.
Use the function to predict the life expectancy of males in 2006.
E(15)= ___ round to the nearest tenth.
Thank you so much for helping me.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
In 1991 the life expectancy of males in a certain country was 63.2 years.
In 1996 it was 65.7 years.
:
Find the slope
In 1991; x1=0 and y1=63.2
In 1996; x2=5 and y2=65.7
:
Find the slope (m) using the slope equation: m = %28y2-y1%29%2F%28x2-x1%29
m = %2865.7-63.2%29%2F%285+-+0%29%29 = %282.5%29%2F%285%29 = .5
:
Use the point/slope formula to write the equation; y - y1 = m(x - x1)
y - 63.2 = .5(x - 0)
y = .5x + 63.2
:
Let E represent the life expectancy in year t, and let t represent the number of years since 1991.
E(t) = .5t + 63.2, The linear function E(t) that fits the data
:
Use the function to predict the life expectancy of males in 2006.
E(15)= .5(15) + 63.2 round to the nearest tenth.
E(15) = 7.5 + 63.2
E(15) = 70.7 life expectancy in 2006