Final answer:
The total cost Joshua paid for the movie rental, represented by the function R(x), is $2.25x + $4.49, where x is the number of days the movie is returned late.
Step-by-step explanation:
Joshua rented a movie for $4.49 from Cinema Rentals, with an additional late fee of $2.25 per day if not returned by the due date. If Joshua returns the movie x days after its due date, the total cost, R(x), he paid for the movie rental includes both the original rental cost and the late fees. The proper function to represent this would be R(x) = $2.25x + $4.49, where $4.49 is the initial cost of the rental and $2.25x is the accumulated late fee after x days.