To find range, you must find the largest number in your data, and subtract it by the smallest number in your data.
In this case...
the Largest (20) - smallest (0) = Range
If a line is parallel to the x -axis, that means the formula is going to be y=a, y is going to be the same for all points.
We have the point where y coordinates = -2,
so the formula of the line y = -2.
If you keep getting money he wont catch up, but if not he'll get $7.14 a day up to $100. He will be pass you so you will take out some days so you both are at $75 on the 4 day of the next day you guys will be close he will have $78.56.