Answer:
k = $0.50
Step-by-step explanation:
The data that we have is:
Rocko paid: $12.50 for 25 tickets.
Louisa paid: $17.50 for 35 tickets.
Now, the question asks to find the constant of proportionality.
A proportional relation can be written as:
y = k*x
where k is the constant, and in this case, y is the price and x the number of tickets bought.
Then replacing with the values above, we have:
$12.50 = k*25
then:
k = $12.50/25 = $0.50
And the other data:
$17.50 = k*35
K = $17.50/35 = $0.50
So we have the same k in both cases, this means that the constant of proportionality is k = $0.50