The table shows the cost of movie tickets based on the number of tickets purchased. PLEASE HELP ME Number of Tickets Cost

2 $17.00

3 $25.50

4 $34.00

5 $42.50

Based on this proportional relationship, find the constant of proportionality (r). Using the value for r, enter an equation that will calculate the cost (y) of x movie tickets in the form of y=rx. The answer is not y=8.5 Please help the one who gives me the correct answer will get brainliest