The number of rides is the independent variable, and the total cost is the dependent variable. (fourth option)
The independent variable is the variable whose value is not dependent on any variable.
The dependent variable is the variable whose value depends on another value. The total cost of the ride depends on the number of rides and the cost per ride. This makes total cost the dependent variable.
The equation that relates total cost to the number of rides is:
Total cost = number of rides x cost per ride
$21.50 = $0.50 x r
$21.50 = $0.50r
To learn more about independent variables, please check: https://brainly.com/question/26287880
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