Answer:
[tex]y = 1125x+30000[/tex] --- The equation
The median income in 2030 is $75000
Step-by-step explanation:
Given
Represent years since 1990 with x and the income with y.
So, we have:
[tex](x_1,y_1) = (0,30000)[/tex] --- In 1990
[tex](x_2,y_2) = (16,48000)[/tex] --- In 2006
Solving (a): Express as a function.
First, we calculate the slope
[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
[tex]m = \frac{48000-30000}{16-0}[/tex]
[tex]m = \frac{18000}{16}[/tex]
[tex]m = 1125[/tex]
The equation is then calculated as:
[tex]y = m(x-x_1)+y_1[/tex]
This gives:
[tex]y = 1125(x-0)+30000[/tex]
Open bracket
[tex]y = 1125x-0+30000[/tex]
[tex]y = 1125x+30000[/tex]
Solving (b): Income in 2030.
In 2030, x = 40.
Substitute 40 for x in [tex]y = 1125x+30000[/tex]
[tex]y = 1125*40 +30000[/tex]
[tex]y = 45000 +30000[/tex]
[tex]y = 75000[/tex]
Solving (c): The significance of the slope.
In (a), the slope is calculated as 1125.
This implies that the yearly rate is $1125
