Question

The Skeeters Baseball team charges $7. per ticket plus $3. processing fee for each order. Is the cost of an order proportional to the number of tickets ordered? Explain how you know.
Tickets | Price
1 | 10
2 | 17
4 | 31
5 | 38
10 | 73

Answer 1

We are given : Per ticket cost = $7.

Processing fee of each order = $3.

Total cost of order including number of tickets costs = 3 + 7* number of tickets.

We are given table : Tickets | Price

1 | 10

2 | 17

4 | 31

5 | 38

10 | 73.

Let us rewrite that table according to the rule 3 + 7* number of tickets.

Tickets | Price

1 |  3 + 7*1 = 10

2 | 3 + 7*2 =17

4 | 3 + 7*4 = 31

5 | 3 + 7*5 = 38

10 | 3 + 7*10 = 73.

We can see that costs are proportional accoriding to the rule :

Total cost of an order =  3 + 7* number of tickets.

Let us explain it by one more way..

We can explain it by applying slope formula.

$m=\frac{y_2-y_1}{x_2-x_1}$

Plugging values in above formula by taking (1,10) and (2,17) coordinates form above table, we get

$m=\frac{17-10}{2-1}=\frac{7}{1}$

By taking (2,17) and (4,31) coordinates form above table, we get

$\frac{31-17}{4-2}=\frac{14}{2}=\frac{7}{1}$

We got same ratios for slope 7/1.

Therefore, we can say the cost of an order proportional to the number of tickets ordered.