Y=-4/5x+1 is the equation for bc
To figure this out you can do 7.2/8.2, because you are trying to figure out how much of the total was used, and percentages would not be more than 100%. Doing this you would get ~.878. To convert this to a percent, you would just multiply it by 100, which would give you 87.8%. The question states to round to the nearest whole percent, leaving you with 88%. This means that 88% of the revenue was spent.
Hope that helped, don't be shy to comment on this if you have any questions about my explanation :)
