Question 328863
In 1992, the life expectancy of males in a certain country was 66.8 years.
 In 1996, it was 70.5 years. Let E represent the life expectancy in year t and
 let t represent the number of years since 1992.
:
Find the slope
In 1992; x1=0 and y1=66.8
In 1996; x2=4 and y2=70.5
:
Find the slope (m) using the slope equation: m = {{{(y2-y1)/(x2-x1)}}}
m = {{{(70.5-66.8)/(4 - 0))}}} = {{{(3.7)/(4)}}} = .925
:
Use the point/slope formula to write the equation; y - y1 = m(x - x1)
y - 66.8 = .925(x - 0)
y = .925x + 66.8
:
therefore:
The Linear function E(t) that fits the data is.
E(t)= .925t + 66.8
:
Use the function to predict the life expectancy of males in 2005
t = 2005 - 1992 = 13 
E(13) = .925(13) + 66.8
E(13) = 12.025 + 66.8
E(13) = 78.8