Rayna is building a tapered staircase using wooden boards. The bottom stair is 3 1/2 ft wide, and the top stair is 2 1/6 ft wide. Each stair is 4 in. shorter than the one below. What is the total length of wooden boards Rayna needs for the stair tops, in feet? Enter your answer in the box as an improper fraction. *Improper fraction: a fraction in which the numerator is greater than the denominator, such as 5/4.