Exercise 7.22: mult-by-scalar In Exercise 3.1, we called a list of numbers an n-tuple. Using flat-recur, define a procedure mult-by-scalar that takes as its argument a number c and returns a procedure that takes as its argument an n-tuple ntpl and multiplies each component of ntpl by the number c. Test your procedure on: ((mult-by-scalar 3) '(1 -2 3-4)) = (3-6 9 -12) ((mult-by-scalar 5) '()) ()