Write an equation in slope-intercept form that describes the relationship between the number of minutes, x, and the amount charged, y.​

y = 1/20x + 6

Step-by-step explanation:

The number of minutes is your x-value. The amount charged is your y-value.

Let's convert the numbers in the table into coordinates.

(30, 7.5)

(120, 12)

(220, 17)

Now, we will take two points and use the slope formula to plug into the slope-intercept equation: y = mx + b

I chose the first and last points given. All three points do not lie on the same line, but using the first and last point should be closer to the line of best fit.

(30, 7.5) & (220, 17)

m = (y₂ - y₁) / (x₂ - x₁)

m = (17 - 7.5) / (220 - 30)

m = (9.5) / (190)

m = 0.05 = 5/100 = 1/20

m = 1/20

Plug m into your equation.

y = 1/20x + b

To find b, plug in a point for x and y.

17 = 1/20(220) + b

17 = 11 + b

b = 6

Plug b into your equation.

y = 1/20x + 6

Hope this helps!