Answer: $4.50
Step-by-step explanation:
Based on the question, we are going to solve this using direct proportion. The formula will be:
y = kx
where,
y = Money spent = $18
x = number of games played = 4
k = constant of proportionality
Note that we can use either the amount spent last week or the amount spent this week since the bowling games costs the same amount of money.
Since y = kx
18 = 4k
k = 18/4
k = $4.50
The constant of proportionality is 4.50