Answer:
The linear equation giving the median salary y in terms of the year x is:
y = 110,684.5x + 457,200
Explanation:
For calculating the linear equation first we need to calculate the slope of the equation represented with an m, the formula is the following:

As in the problem it is said, x will represent the time so:
x1 will be the initial year so x1=2000
x2 will be the final year so x2=2008
Now the salary will be represented with the y so:
y1 will be the salary for the year 2000 then y1 = $457,200
y2 will be the salary for the year 2008 then y2 = $1,342,576
Then replacing the values in the equation we will have the following expresión:

Now we have to replace this values in the following formula for linear equation
y-y1 = m(x-x1)
As they say that x represent 2000 as the initial year then when we replace we will have the following expresion
y - 457,200 = 110,684.5(x - 0)
y = 110,684.5x + 457,200
To verify our equation we can check for the salary in 2008 as it is 8 years after of 2000 x=8 then
y = 110,684.5 (8) + 457,200
y = 885,476 + 457,200 = 1,342,676