Word problem

Question

a federal Commission's annual report on cigarette sales and advertising shows the major cigarette manufacturers spent 14.2 billion dollars on advertising and promotional expenditures in 2003, and increase of 2.27 billion dollars from 2002 and the most ever reported to the Commission. Write a linear equation that represents the expenditure in billions of dollars as a function of the number of years after 2000.

Answer 1

Michael,

The first step is to set your variables.

 

x = years since 2000

y = billions of dollars spent

 

The next step is to find the slope of this linear equation.

 

m = Δy/Δx = 2.27/1 = 2.27

 

Finally we use the point slope equation to finish up.

 

y - y₁ = m(x - x₁)    use the given point  (3, 14.2)

 

y - 14.2 = 2.27(x - 3)

y = 2.27x - 6.81 + 14.2

y = 2.27x + 7.39