A bag contains only red and blue marbles. There are a total of 36 marbles in the bag. There are 5 red marbles for every 4 blue marbles in the bag. A student removes 1 blue marble from the bag. The student reasons that there are now 5 red marbles in the bag for every 3 blue marbles since 4-1=3. Explain the error in the student’s reasoning. Compute the correct ratio of red to blue marbles after the student draws 1 blue marble. Show your work or explain your answer.