
Shaina B. answered 10/01/19
12-year Mathematics Teacher Veteran
We will use slope intercept form: y=mx+b
X and y are provided in the problem: x = monthly sales and y = compensation
We will have to find m (Slope), which in this problem represents the commission percentage, and b (y-intercept), which represents the the base salary.
x1 y1 x2 y2
(50000, 3200) (60000, 3600)
m = (y2 - y1) / (x2 - x1)
m = (3600 - 3200) / (60000 - 50000)
m = 400 / 10000 --> 4/100 (4%)
so m = 4% (which can be written as 0.04 or 4/100)
To find b, we have to take one of our ordered pairs [ (50000, 3200) or (60000, 3600) ] and plug it into the equation, y=mx+b.
Let's use (x2, y2) or (60000, 3600)
y = mx+b
3600 = 0.04(60000)+b
3600 = 2400+b
1200 = b
so b (the base salary) is = 1200
The equation is y = 0.04x + 1200