#| BEGIN (Write your solution here) |#
(define (make-center-percent c p)
  (make-center-width c (* (/ c 100) p)))

(define (percent i)
  (* 100 (/ (width i) (center i))))

(define (make-center-width c w)
  (make-interval (- c w) (+ c w)))

(define (width i)
  (/ (- (upper-bound i) (lower-bound i)) 2))
#| END |#