7 dollars and 30 cents becuse 4 wuarters equals 1 dollar plus the 5 other equals 6 dollars and then you have 2 quarters left which equals 6 dollars and 50 cents plus the 8 dimes/80 cents and 6 dollars and 50 cents plus 80 cents equals 7 dollars and 30 cents
the cost is proportional to the number of people because a constant value 9.50 exists where each measure of the number of people multiplied by this constant gives the corresponding measure in y
