Given the Following Results

Short Answer

Given the following results
Life expectancy = 1+2GDP - 0.01GDP²
where GDP is in thousands (meaning a GDP of $60 signifies a GDP of $60,000), answer the following:
a. The predicted increase in life expectancy of GDP increase by $1 from $40.
b. The predicted increase in life expectancy if GDP increase by $1 from $100.
c. The predicted life expectancy in a country with a GDP of 50.
d. Give a simple explanation for the use of a polynomial model in order to model the relationship between life expectancy and GDP.