Question 1144193
linear function is y = mx + b in slope intercept form.
m is the slope
b is the y-intercept
the slope is the change in y divided by the corresponding change in x.
the y-intercept is the value of y when x = 0.


37 minutes = $15.42
53 minutes = $17.18


x is the minutes
y is the cost.


you have two points to consider.
they are (x1,y1) = (37,15.42) and (x2,y2) = 53,17.18)


the change in y is 17.18 - 15.42 = 1.76.
the corresponding change in x is 53 - 37 = 16.
the slope is 1.76 . 16 = .11


y = mx + b becomes y = .11 * x + b
replace x and y with either one of the coordinate points to solve for b.
i chose (37,15.42).
the equation becomes 15.42 = .11 * 37 + b.
solve for b to get b = 15.42 - .11 * 37 = 15.42 - 11.35


your equation becomes y = .11 * x + 11.35


when x = 0, y = 11.35
when x  = 37, y = .11 * 37 + 11.35 = 15.42
when x = 53, y = .11 * 53 + 11.35 = 17.18


the equation looks good.
for 39 minutes, the total cost will be .11 * 39 + 11.35 = $15.64.


the equation can be graphed.
the equation to be graphed is y = .11 * x + 11.35
here's what the graph looks like.


<img src = "http://theo.x10hosting.com/2019/082501.jpg" alt="$$$" >