What is the difference between independent variable and dependent variable? I’m confused as to if time is the independent variable or the cost is.

The boat rental charge is the sum of a fixed fee and an hourly rate.

The fixed fee is just a number chosen by the company. Anyone renting a boat, for any number of hours, must pay the same fixed fee as part of the rental charge.

The cost per hour varies according to the number of hours. For 1 hour, you add a certain amount based on the cost per hour to find the total charge. For 2 hours, you add the correct hourly fee for 2 hours, etc. The number of hours is any number you wish to rent the boat for. It is based simply on what the customer wants. Once the number of hours is chosen, the hourly fee can be calculated based on that number of hours. The number of hours does not depend on any calculation. It is independent of any calculation. The number of hours is the independent variable. Once a specific number of hours is chosen, then the hourly fee is calculated. When you add the hourly fee to the fixed fee, you get the cost. The cost depends on the number of hours. The cost is the dependent variable.