Final answer:
The cost of riding in a taxi and purchasing carnival ride tickets are proportional, while the cost of concert tickets and indoor-cycling classes are non-proportional.
Step-by-step explanation:
The situation of the cost of riding in a taxi can be classified as proportional. The starting cost of $6 and the additional charge of $0.85 per half mile are directly related. For example, if the distance increases, the cost also increases proportionally.
The situation of the cost of purchasing carnival ride tickets at a price of $20 for a pack of 10 can also be considered as proportional. The cost and the number of tickets are directly related. As the number of packs increases, the cost increases proportionally.
However, the situation of the cost of purchasing concert tickets for $18 each with a $4.50 service fee on the entire transaction is non-proportional. The fee is a fixed amount that is added to the cost, regardless of the number of tickets purchased. Therefore, the relationship between cost and number of tickets is not proportional.
The situation of the cost of indoor-cycling classes at $8 per class with a $100 enrollment fee can also be classified as non-proportional. The enrollment fee is a fixed cost that is added to the per-class cost, irrespective of the number of classes attended. Thus, the relationship between the cost and the number of classes is not proportional.
Learn more about Proportional and non-proportional situations in cost calculations