Answer:
Step-by-step explanation:
In order to find how much credit is left after 92 minutes, we need to
1. Figure out the equation that describes this graph (since we don't know the y-intercept)
2. Find the credit remaining after 92 minutes using the equation formed.
<h2>Figuring out the equation of this graph:</h2>First things first is to figure out the slope of this graph. Since this is a linear function, the slope will remain constant, and we can note something about slope here.
The slope of a line will be it's change in x divided by its change in y, often referred to with a formula.
Since we know two points on this graph, we can find the changes in the x and y then divide for the slope.
Since minutes used is the x, and credit left is the y, we have two points.
(41, 19.26) and (68, 15.48).
- The change in y is -3.78, as
, and we decreased, so -3.78.
- The change in x is 27 as
, and we increased.
The slope will then be which comes out to be -0.14.
Now that we know the slope, that means our equation will look something like - however, we still have b to solve for!
To solve for it, we can substitute one of our points in - let's do (41, 19.26) - to the equation and solve for b.
Now that we know that b = 25, we can plug it into our equation, <u><em>making the final equation that represents this scenario</em></u>
Now that we know the equation to our graph, we can substitute in 92 minutes as the x value to find our y value (credit left).
Therefore, after 92 minutes, the amount of credit left is $12.12
Hope this helped!