Need help with a function in DrScheme

I can write the recursion version correctly need help with writing a do loop in DrScheme.

After the do loop the variable x is sent to car L intially and then is updated to first element of everything but first element in list.

(Toggle Plain Text)
(define (sumiteration L)
  (do ((x (car L) (car(cdr L))))
    ((null? L))
    (set! sum (+ sum x)))
)

The direct answer might be:

(define (sumiteration someList)
  (do ((sum 0)
       (L someList (cdr L)))
    ((null? L) sum)
    (set! sum (+ sum (car L)))))

1) There was a sum referenced in the (set! sum (+ sum x)) that was not previously defined.
2) Nothing advanced the list L.

For a reasonably short input list, you might:

(apply + your-list-of-numbers)

It may also be of interest to use srfi/1 reduce which won't have a problem with large lists.

(require srfi/1)
(reduce + 0 your-list-of-numbers)