Question

The U.S life expectancy of a baby born in 1960 was 69.8 years. For a birth year of 2010, the U.S life expectant was 78.5 years. Let Y be the US life expectancy for a baby born in the year x, where x=0 represents the year 1960. What would the life expectancy for a baby born in the year 2020 be? What is the slope and what does it represent?

Answer 1

clearly the slope is (78.5-69.8)/(2010-1960) = 0.174

so, starting with x=0 for 1960,

y = .174x + 69.8

Now just plug in your numbers